Current Medicinal Chemistry

FDA defined “botanicals” as products of plant materials, algae, macroscopic fungi, and their combinations and considered them as finished, labeled products containing vegetables as ingredients, that can be used as conventional foods, dietary supplements, drugs, cosmetics, or medical devices depending on its route of administration, formulation, safety and intended use [1, 2]. Today, the use of medicinal plant remains widespread, and a significant portion of the world's population utilizes herbal natural products and supplements as the primary mode of healthcare [3,4]. In the United States, for instance, nearly 20% of adults and 5% of children utilize botanical supplements to treat different diseases. The increase in adoption of herbal remedies may be ascribed to: a general preference of natural therapies and aversion for other interventions like surgery, allopathic medicines etc; inclination towards self-medication based upon experience; affordable cost of herbal medicines and ease of availability; side effects associated with conventional medicines (especially in cases of chronic problems) and growing promotion of herbal medicines [4]. Botanicals in medicine are usually recommended for disease prevention and to maintain good health, while rarely their use is suggested for acute and/or life-threatening problems. More recently, it is observed a growing use of herbal medicine when conventional medicine is ineffective or for pain palliation in case of long-standing problems like cancer, arthritis etc. [5]. Also cosmetic market has been influenced by botanicals. In particular, it has been observed a growing trend in incorporating antioxidants in sunscreens and skincare products to replenish the natural reservoirs in the skin [6]. This “new renaissance” of herbal product obliges us to employ them with a real scientific method. Researchers having access to innovative technologies can optimize the use of herbal ingredients in natural formulations, to give safety and efficacy to the formulation across a scientific view, validating the traditional use, with no previous scientific evidence. On these basis, this special issue is aimed to give an overview on the current state of botanicals research, in order to collect recent scientific data on the development of pharmaceutical products, cosmetics and nutraceuticals. The attention is focused on the chemical composition, biological activities [7-11] and nutritional aspects of new herbal product [8, 11,12] and on the application of innovative technologies or formulative approaches to improve their stability and bioavailability [8-10, 12-15]. Readers will find information about new natural products endowed with healthy activities. Flaxseed oil, for instance, is a very important product characterized by anti-oxidant, antiinflammatory and anti-dysmetabolic effects and has been evaluated for a potential application in different diseases [8]. Brassica vegetables also possess anti-oxidative properties and are associated with the risk reduction of chronic diseases including cardiovascular diseases and cancer [9]. The focus of the present special issue is also on some indigenous underutilized wild edible plants, such as Pereskia aculeate, a natural diet supplement studied as “novel food” in virtue of its high nutritional value [10] and Momordica cochinchinensis, a super fruit, of the functional food industry [11]. Finally, our readers will find interesting examples of innovative delivery strategies to increase the bioavailability of natural active compounds from vegetable sources [12]. Extensive discussion on this special issue about different nanocarriers for the delivery of natural products, functional foods, dietary supplements and herbal medicinal products is also addressed [13-15]. The Editors thank the authors who contributed to this special issue with high-quality manuscripts that increased its value.

The aim of this issue is to present some important contributions of researchers mainly from the Academia about the drug design and discovery of bioactive compounds on Neglected Diseases. The researches have been developed by important and specialized Brazilian and foreign groups dedicated to the search for new bioactive compounds in some of the most important Neglected Diseases worldwide. The diseases involved are: Chagas disease, leishmaniasis, malaria, tuberculosis, dengue, schistosomiasis and leprosy. Well-known molecular targets and also new ones are comprehended in the subtopics in general. Then, rational design, especially SBDD – Structure Based Drug Design – is the subject of some topics, and, in addition, LBDD – Ligand Based Drug Design is involved in some topics. Molecular modification as bioisosterism, molecular hybridization and prodrug design are used as approach to design some leads and hits, described for their potential activity on Neglected diseases. Polypharmacology and also drug repositioning are discussed concerning its importance on Neglected Diseases.

Diabetes mellitus is defined as a pathological condition characterized by unbalanced blood glucose levels due to the disruption in the cell signaling linked to its main regulator factor, insulin. An initial classification of patients was done according to an impaired insulin body function, thus patients were considered as type 1 and type 2 diabetic [1]. Nevertheless, besides the progression in the knowledge regarding this syndrome, new subtypes have been identified and designed. On the other hand, the development of molecular biology, biotechnology and genetic tools has provided to the scientific community the discovery of new molecules and proteins, as well as genes, that have been associated with the development or affect the progression of this syndrome and, in turn, will force the description of new subtypes of diabetes mellitus. In fact, a diversity of the available diagnostic tools, together with a reduction in the cost of these molecular and genetic diagnostic procedures, have made the physicians to change the way of approaching different diseases; the concept of a personalized medicine is becoming more relevant and it is gaining more support. The basis of this new approach is the comprehensive information available in the literature regarding the molecular pathways and/or proteins altered, or involved in the development of a particular disease. For instance, the discovery of the regulatory function of certain miRNAs opens a new field in the diagnosis of certain diseases such as cancer, so it would also assist in case of patients suffering from diabetes mellitus [2, 3]. In this special issue, we provide an updated overview of new molecular and genetic markers (such as the identification of new miRNAs) that can be used for the diagnosis and monitoring of the progression of the several complications linked to diabetes mellitus, like thrombosis, kidney failure, neurological complication, etc. Furthermore, readers could find information about the latest diagnostic tools, and/or possible future therapies based on the use of stem cells and antagomirs [4-7]. We have also included information regarding the close relationship between adipose- tissue and pancreas, by enumerating several adipokines that link both these tissues in order to regulate or integrate the metabolism and bioavailability of either glucose or lipids [8]. In addition to the molecular marker described above, we have included reviews including some clinical aspects, as well as some references to more patophysiological aspects such as alteration in platelet function that compromises the cardiovascular system, and other diabetes mellitus linked complications such as heart failure and vascular myopathy [9, 10]. It is also worth mentioning that some experts in the field of melatonin provide us with information regarding the contribution of this hormone to modulate the impact of hyperglycaemia in diabetic patients [11]. Finally, related to the vascular dysfunction presented in diabetic patients, in-depth knowledge of the contribution of diabetes mellitus to the appearance of male reproduction dysfunction is further explained. In this review, authors also describe the benefits and/or side effects on male reproduction of some drugs that are currently in use for the treatment of diabetes mellitus [12]. The editors would like to thank all the contributors of this issue, as well as the reviewers whose contributions enhanced the quality of the manuscripts published in this special issue.

Computational approaches have been greatly appreciated as an important pillar of drug discovery and development. This special issue compiles a series of review articles that, in the era of personalized medicine, advance our understanding and foster the identification of appropriate in silico resources in this area. Computer-Aided Drug Design (CADD) has been at the forefront of the search for new drug targets and design of therapeutic compounds for a long time. Bruno et al. (2017) analysed the early phases of the drug-discovery pipeline and discussed the pathway from disease choice to lead optimization [1]. The challenges of individual steps in the discovery pipeline are assessed, as well as computational tools and in silico resources widely in use. Successful results of pharmaceutical companies in the recent period show the benefits of technological advances that translate into more efficient and accurate computational tools. On the other hand, analyses of major failures show that we are still facing the challenge of treating the targets in a more physiological context. This compendium of the drugdiscovery process is valuable both as an overview to the professionals and as an educational resource. Vucicevic et al. (2017) discussed in silico techniques used in rational drug design of antineoplastic agents and presented optimal combinations of computational methods for design of safer and more efficient antineoplastic drugs [2]. An overview of QSAR studies applied in development of modulators of epigenetic targets and inhibitors of Bcl-2, Bcl-xl, mTOR inhibitors, and CDK1 is provided. There are generally two distinct approaches to computational drug design, structure based and ligand based. The authors discuss the successful project as well as technical requirements of both virtual screening and docking techniques. Protein-Protein Interactions (PPI) underlie key cellular processes and offer immense possibilities to the search for druggable interactions as well as for off-target candidates. In their review, Gemovic et al. (2019) described public computational tools for PPIs that rely on statistical and machine learning methods [3]. The authors tested the capacity of several popular tools to predict newly discovered interactions and provide guidelines with background information necessary to understand the results. In addition to that, this review presents a detailed overview of databases and other public resources that store information of both experimental and predicted PPIs. For some time, PPIs were considered difficult drug targets, but due to the numerous compounds in clinical studies this perspective is changing, thus emphasizing the importance of PPI bioinformatic tools for the drug discovery community. Protein aggregation into β-sheet-enriched insoluble assemblies has been found to be associated with both systematic or organ diseases, such as Alzheimer's, Huntington's, Parkinson's, type II diabetes and prion diseases. Protein aggregation also represents a barrier in the design and development of protein-based therapeutics. Parales and Ventura (2017) reviewed bioinformatic tools for prediction of the targetable proteome prone to aggregation which are based either on sequence or on structural information [4]. Although some of the sequence based algorithms rely on rather simple principles, they are capable of efficiently detecting aggregation of nucleating peptides. Structure based algorithms leverage on ever-increasing tertiary structure data. AGGRESCAN 3D is a popular web tool that identifies residues susceptible to aggregation and provides an option for testing amino acid substitutions that increase solubility. The application of aggregation prediction methods enhances our understanding of principles that govern aggregation and enables control of the solubility of biotherapeutics. In the era of Big Data [5], the topics tackled in the special issue: “Recent in silico resources for drug design and discovery” will become even more significant, particularly with a focus on making the process of choosing the drug candidate more efficient, and on the use of various available data to better assess attrition risks.

The steadily increasing epidemiological prevalence of age-related neurodegenerative diseases and the deepening of knowledge on basic mechanisms underlying physiologic and pathologic aging processes of the brain account for the need of constant up to date of data emerging from fundamental, translational and clinical research. Accordingly, original data from Bonfiglio et al. [1] offer a measure of the impact of environmental stimulation on the release of neurotransmitters (noradrenaline, glutamate and gamma amino butyric acid (GABA)) suggesting that these undergo different adaptations during aging and that they are differently tuned by “cognitive training”. The impact of “cognitive training” on neurotransmitter exocytosis might account for the cellular events involved in the reinforcement of “cognitive reserve” in both young and old animals. Although translation from rodent studies to clinical situation could be difficult, the results from pre-clinical models are of high clinical relevance, since they may allow a better understanding of the effects of environmental interventions in aging-associated chronic derangements in mammals. Also, they improve our understanding as to whether “cognitive training” promotes compensatory effects or, alternatively, if it elicits genuine recovery of neuronal defects. There is no doubt that everyone experiences adverse events during life that impact both the health and quality of life. However, trajectories of health in aging can vary significantly depending on the individual. According to this hypothesis, Brivio et al. [2] envisage that a reduction of resilience may underlie an increased risk to develop pathological conditions during aging. In line with this idea, fragility in elderly would be the consequence of reduced function and responsiveness of biological systems, crucial for coping with stressful events. For the authors, it is therefore fundamental to identify and characterize the mechanisms that may contribute to the resilience or the vulnerability to stressful events, since such mechanisms may be significantly altered in the aged brain. However, a major gap in this field of research is that the studies are limited to assess molecular alterations under basal or resting conditions, without information on, if and how these functional impairments result in lack of stress responsiveness. The investigation of these mechanisms will be critical to identify genes and pathways the changes in which may contribute to achieve a better understanding of the risk architecture for age-related vulnerability and may represent potential targets for the development of novel pharmacological interventions. In the above streamline of thoughts, Cerri and Blandini [3] report on dysregulation of the autophagic pathway as a contributing factor to PD pathogenesis via α-synuclein accumulation. Heterozygous mutations in the GBA1 (glucosylceramidase beta 1) gene are currently recognized as the most relevant risk factor for the disease pointing to lysosomal defects as major players in the PD-related impairment of the autophagic process. Preclinical findings support the use of therapeutic agents boosting autophagic activity, as potential disease-modifying agents. However, a deeper understanding of the mechanisms that may lead to autophagy defects in PD will be required to facilitate the design of new therapeutic interventions. The multifactorial nature of the disease allows this consideration to be extended to other mechanisms involved in PD pathogenesis, such as neuroinflammation oxidative stress, and mitochondrial defects. Kustrimovic et al. [4] discuss the evidence accumulated supporting a fundamental role for neuroinflammation in PD; also, they originally contribute to the understanding of the active participation of peripheral immune mechanisms. The definition of the peculiar profile of CD4+ T naive and memory cells with likely consequent proinflammatory changes of immune system in PD patients suggests that these peripheral immune challenges can exacerbate the process of neuroinflammation and hence the symptoms of the disease also providing the rational basis for the proposal of immunotherapy for the treatment of PD. Mancino et al. [5] demonstrate as the development of advanced neuroimaging techniques allows some degenerative diseases, considered of exclusive ocular relevance, to be associated with neurodegenerative phenomena of the Central Nervous System (CNS). Thus, a strong connection between the stage of glaucoma and alterations of the optic nerve and of the optic radiations has been assessed using diffusion tensor MRI (DT-MRI). In particular, with this technique damage is measured by extrapolating from the images two numerical parameters: the Mean Diffusivity (MD) and the Fractional Anisotropy (FA). The finding showing increased values of MD and decreased values of FA, measured in the retrobulbar portions of the optic nerve of patients with glaucoma, suggests that also the extra bulbar portions of the optic nerve are affected by glaucoma. Interestingly, the analysis of DT-MRI parameter in glaucomatous patients at different stages of the disease showed that alterations in the early glaucoma are predominantly located at the level of retro-laminar region while, in the advanced stages, they also affect the distal portion of the nerve. Glaucomatous alterations may therefore be an expression of a neurodegenerative disease, which from the central areas extends to the retina. In this regard, recent studies using MRI reported that glaucoma affects not only the RGCs, but also the CNS with a similar mechanism found in other neurodegenerative diseases such as Alzheimer’s disease. The latter disease accounts for approximately 50% of all cases of dementia and, in spite of the great effort, disease- modifying drugs are not available yet. Adherence to the current therapy of cognitive decline is needed for a better control of the disease and this is proven to reduce, though it does not abolish, the associated Behavioural and Psychological Symptoms of Dementia (BPSDs). On this aspect, Scuteri et al. [6] discuss how this cluster of symptoms, remarkably affecting patients’ health-related quality of life (HRQL), is tightly associated to pain states. Actually, antipsychotics are the only treatment for BPSDs though they are able to manage aggression but not agitation and they cannot control pain. Clinical trials with Melissa officinalis and Lavandula officinalis have demonstrated efficacy in handling BPSDs but strong evidence to offer relief from pain is lacking. At variance with the latter, Bergamot Essential Oil (BEO) is endowed with strong analgesic activity implicating pharmacological mechanisms, i.e. enhanced autophagy, a process undergoing derangement in chronic pain lending support to the pharmacological basis for clinical translation of aromatherapy with BEO in the treatment of BPSDs. Altogether, the issue offers the perfect setting to discuss very interesting topics and to share studies and knowledge, thus widening our understanding of normal and diseased aging and giving rise to novel research lines for the development of better neurotherapeutics.

Nutrients are digested and absorbed in the body at different locations in the gastrointestinal tract, and diet plays a key role in bringing fats, proteins, carbohydrates, fiber, micronutrients including vitamins, and antioxidants in close contact with the intestinal mucosa where absorption occurs. The human intestinal microbiota, through its diversity and functions in health and disease, is greatly involved by providing substrate metabolism of branched-chain and aromatic amino acids, components of diet, drugs, bile acids, xenobiotics, biosynthesis of short-chain fatty acids, steroid hormones, neurotransmitters, and vitamins [1-4]. A great deal of evidence has shown that nutrients act as mediators contributing to the pathophysiology of biological processes, including oxidation, inflammation, and organ dysfunction. Moreover, their synergistic mechanisms result in greater effects, thus highlighting the importance of focusing on food groups, in addition to nutrients [5]. In this respect, diet can be regarded as a type of beneficial agent, and currently much attention is given to the contribution of diets to health maintenance as well as to the complex pathogenesis of diseases [6]. Thus, nutrition should be placed at the forefront of public health programs as a cost-effective means to prevent a number of chronic diseases, which include metabolic disorders (obesity, type 2 diabetes), cardiovascular diseases (coronary heart disease, hypertension and stroke) [7-9], cancer [10, 11], liver disorders, dental diseases and osteoporosis [12-14]. With this scenario in mind, the Editors of the present issue of Current Medicinal Chemistry have gathered valuable evidence from a large number of experts worldwide in order to focus on “Medicinal” diets and their role in health and disease. From a basic science perspective, this area provides opportunities to advance our understanding of related pathophysiological mechanisms. From a clinical perspective, this opens new avenues to provide patients with an active and empowering role in health maintenance, with numerous positive repercussions. In Section 1, the Basic Implications are Examined. Teixeira et al. discuss the role of four dietary polyphenols – resveratrol, curcumin, epigallocatechin-3-gallate (EGCG) and quercetin – in molecular pathways regulated by mitochondria and their potential impact in human health. The mechanisms underlying the polyphenols’ beneficial effects include, among others, the attenuation of oxidative stress, the regulation of mitochondrial metabolism and biogenesis and the modulation of cell-death signaling cascades, among other mitochondrial-independent effects. Wang et al. focus on the complex molecular mechanisms linking the neurohormonal response of the gallbladder to the gastrointestinal hormone cholecystokinin (CCK), which, under food stimulation, initiates gallbladder contraction and bile secretion, thus preventing the precipitation of excess biliary cholesterol and gallstone formation. Gallbladder- specific CCK-1R-selective agonists may provide an efficacious novel strategy for preventing gallstone formation by promoting gallbladder emptying, particularly in subjects with gallbladder contractile dysfunction, e.g. patients with celiac patients as well as patients on total parenteral nutrition. Silva & Jones review the effect of “functional foods” on metabolic control, and potential implications in health and disease. Given the high and increasing incidence of glucose intolerance and type 2 diabetes related to overnutrition in Westernized societies and the potentially significant role of diet and food awareness in preventing or reversing this condition, the review will focus on those food components or supplements that specifically improve glycemic control. Vergani focuses on free fatty acids (FA) which are the major mediators of hepatic steatosis; patients with NAFLD have elevated levels of circulating FA which correlate with disease severity. Steatosis is a reversible condition that can be resolved with changed behaviors, or that can progress towards more severe liver damage such as steatohepatitis (NASH), fibrosis and cirrhosis. Thus, excess of fatty acids, an essential component of digested foods, essential step in the onset and perpetuation of liver steatosis. Cataldo et al. describe the subtle mechanisms linking the function of Aquaporins (AQPs), a family of membrane channel proteins widely expressed in the human body, to the beneficial action played by some food nutrients and phytochemical compounds. The authors provide an overview of what is known regarding the AQP modulation exerted by healthful dietary patterns and plant polyphenols. In Section 2, the “Clinical Implications” are Reviewed. Di Ciaula et al. discuss the close connection between overweight, obesity, dyslipidemia, insulin resistance and altered cholesterol homeostasis to increased gallstone occurrence. A number of specific nutrients acting as risk factors with respect to gallstone formation include increased energy intake with highly refined sugars and sweet foods, high fructose intake, low fiber contents, high fat, consumption of fast food and low vitamin C intake. On the other hand, high intake of monounsaturated fats and fiber, olive oil and fish (rich in ω-3 fatty acids) consumption, vegetable protein intake, fruit, coffee, moderate alcohol consumption and vitamin C supplementation exert a protective role. Stokes et al. place the burden of non-alcoholic fatty liver disease (NAFLD) into clinical perspective with a focus on the impact of nutrition and cite examples of short-term interventions that assess direct effects of dietary-related components on hepatic steatosis. The main focus is on the three macronutrients, i.e. dietary carbohydrates, fats, and proteins. Surdea-Blaga et al. summarize current knowledge regarding food and gastroesophageal reflux. For example, fat intake increases the perception of reflux symptoms. Regular coffee and chocolate induce gastroesophageal reflux and increase the lower esophageal exposure to acid. Spicy foods might induce heartburn, but the exact mechanism is not known. Beer and wine induce gastroesophageal reflux, mainly in the first hour after intake. For other foods, such as fried food or carbonated beverages data on gastroesophageal reflux is scarce. Similarly, there is limited data on the type of diet and gastroesophageal reflux. Mediterranean diet and a very low carbohydrate diet, by contrast, appear to protect against reflux. Portincasa et al. discuss a frequent functional gastrointestinal disease, namely irritable bowel syndrome (IBS), which can be influenced by foods. Dietary education is essential to deal with foods that are potential triggers for the onset or worsening of symptoms. However, further studies are required to link the ultimate role of diets in different IBS subtypes. Ferri et al. provide evidence that healthy diet and improved dietary practices contribute to reduced chronic disease risk among shift workers. A possible role of education programs on eating behavior as preventive strategies in this group of workers should incorporate several important lifestyle changes. Carbone et al. discuss the role of ethanol as a potential direct cardioprotective agent and update current knowledge on the intracellular mechanism underlying the cardioprotective effects of polyphenols and ethanol. The need for randomized clinical trials able to clarify the potential role of red wine consumption in reducing cardiovascular risk is also discussed. De Angelis et al. address the issue of diet, benefits to human health and activity of gut microbiota. Habitual diet (Western, Agrarian and Mediterranean omnivore diets, vegetarian, vegan and gluten-free diets) drives the composition of the gut microbiota and metabolome. Specific relationships between diet and microbes, microbes and metabolites, microbes and immune functions and microbes and/or their metabolites and some human diseases are being established. Garruti et al. report on nutritional factors, other lifestyle components including excess body fat in interfering with female reproduction and fertility. In an attempt to define “the optimal fertility diet“, the authors will consider the role played by a Mediterranean lifestyle and specific macronutrients (animal and vegetable proteins) on ovulatory disorders and female fertility. Ezquerro et al. discuss the effects of diets on adipose tissue. In obesity, dietary changes should be individualized, tailored to food preferences and allow for flexible approaches to reducing caloric intake in order to increase the motivation and compliance of overweight and obese patients. The review summarizes compelling evidence showing body composition changes, impact on cardiometabolism and potential adverse effects of very-low calorie, low- and high-carbohydrate, high-protein or low-fat diets. Almeda-Valdes et al. discuss the role of diet in patients with the metabolic syndrome, a very common metabolic disorder. The goal of treating metabolic syndrome is to reduce the risk of coronary heart disease and the development of type 2 diabetes. Lifestyle modification therapy combines specific recommendations on diet alone or combined with other strategies. Di Ciaula and Portincasa focus on the dangerous link between diet and contaminants in driving the rise of obesity epidemics. Indeed, maternal diet, intestinal microbiota and chemicals introduced as contaminants with food, are all factors able to increase the risk of obesity. Widely diffused toxics are able to promote obesity in children and adults, mainly by acting on the differentiation pathway linking multipotent stromal stem cell to mature adipocyte, modulating epigenetic factors and influencing a series of mechanisms finally leading to altered dietary habits, increased adipocyte formation and fat storage. The efficacy of primary prevention strategies acting on all these factors might contribute to reversing the continuous rising of the obesity epidemic. Badimon et al. underscore the importance of the link between diet and cardiovascular disease (CVD). Current research places the Mediterranean dietary pattern, rich in fruits and vegetables, as the most cardioprotective, because of its high concentration of bioactive compounds such as unsaturated fatty acids, polyphenols, fiber, phytosterols, vitamins and minerals, which exert antioxidant, anti-inflammatory and anti-thrombotic effects contributing to the delay of CVD initiation and progression. Mastronuzzi and Grattagliano examine the problem of adequate caloric intake as a major determinant of health status especially when degenerative conditions become a predominant risk for difficult-to-treat diseases, as in aging. The maintenance of nutritional status is the best measure to counteract the risk of protein-caloric malnutrition and its complications which often affect elderly populations and frail patients. Attention is placed on certain aspects associated with malnutrition as an indicator of disease severity and health costs in the elderly population. The impact of nutritional interventions and nutrient supplementation on general indices of malnutrition is also discussed as a promising strategy. Altomare et al. review the topic of cholecystectomy, as a condition which can have nutritional and metabolic consequences in the short-term (diarrhea, abdominal pain and bloating) and in the long-term (increased body mass index with metabolic syndrome, gastritis, liposoluble vitamin deficiency). Pathogenic mechanisms behind these disturbances are reviewed and the need for an early post-operative nutritional intervention based on a low-lipid, highfiber diet, is highlighted. In conclusion, the continuously evolving field of nutrition with respect to prevention and treatment, as well as induction and perpetuation of chronic diseases, is central in modern clinical medicine with a myriad of translational implications. We as Editors believe that undergraduate and postgraduate students, residents, researchers, clinicians and nurses alike will enjoy and take advantage from reading the following chapters in Current Medicinal Chemistry. All contributions have been reviewed, include updated bibliographies and current guidelines, and are enriched with concise tables and figures, dealing with the key pathophysiological mechanisms and chemical formulas.

Drug discovery and development, is vital for contribution to human health and for saving the lives. In this regard, enzymes, the active biological catalysts in organisms, are involved in many pathways and speed up or regulate many reactions in the body. Enzyme inhibitors are the compounds interacting with an active gorge of any enzyme to prevent or alter its regular catalytic function in a permanent (irreversible) or temporary (reversible) manner and in competitive or non-competitive mode. Enzyme inhibitors are also of value to treat many diseases at the moment, most of which are in clinical use and, therefore, they have become a very attractive target for drug development and discovery. For instance, glucocerebrosidase inhibitors for Gaucher disease, cholinesterase inhibitors for Alzheimer’s disease (AD) and myasthenia gravis (MS), angiotensin-converting enzyme (ACE) inhibitors for the treatment of hypertension, 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase inhibitors for hypercholesteramia, protease inhibitors for AIDS treatment, monoamine oxidase-A (MAO-A) for depression, tyrosinase inhibitors for hyperpigmentation, and α-glucosidase inhibitors for diabetes mellitus, etc. can be exemplified to underline their role in the treatment of a wide range of diseases. Consequently, designing and discovering novel enzyme inhibitors are a prevalent research approach and an immense number of studies are being published each year. Consistently, the prominence of various enzyme inhibitors has been discussed extensively by many researchers in comprehensive systematic reviews [1-8]. The paper by Anna Boguszewska-Czubara et al., initially introduces structural and functional characteristics of matrix metalloproteinase inhibitors (MMPs) as a large enzyme family in detail. Then, they discuss their vigorous role in the central nervous system (CNS)-related diseases like stroke, Alzheimer’s disease (AD) and vascular dementia, Parkinson’s disease (PD), and multiple sclerosis (MS). They elaborate the role of matrix metalloproteinase inhibitors (MMPs) which play a key role in re-modeling of the extracellular matrix (ECM) and also influence cell differentiation, migration, proliferation, and survival. It covers the information on tissue inhibitors of metalloproteinases (TIMPs) expressed in various structures of adult brain as well as well-known natural endogenous tissue inhibitors of TIMPS through exogenous synthetic ones like (4-phenoxyphenylsulfonyl)methylthiirane (SB-3CT), tetracyclines (e.g. minocycline and doxycycline), batimastat (BB-94), and FN- 439. The authors conclude that more clinical studies are required due to lack of human studies evidencing the effects of MMP inhibitors found in animal models as attractive therapeutic targets [9]. The paper by Miguel D. Ferrer et al. deliberates the latest outcomes on selective cyclooxygenase-2 (COX-2) inhibitors (e.g. non-steroidal anti-inflammatory drugs, NSAIDs) in relevance to inflammatory pathologies characterized by a prolonged pro-inflammatory status, including autoimmune diseases, metabolic syndrome, obesity, atherosclerosis, neurodegenerative diseases, chronic obstructive pulmonary disease, arthritis, chronic inflammatory bowel disease, and cardiovascular pathologies. In fact, COX-2 selective inhibitors have been reported to be a promising approach to counteract the higher inflammatory mediator production induced by over-expressed COX-2 in inflammatory diseases. The authors in their paper briefly covered the structural and physiological properties of COX family, conventional inhibitors of COX-2, their vital role in inflammatory diseases, and their side effects, while they also discussed the imperative role of pure natural or chemically-modified compounds along with examples of medicinal plants in preventing inflammation through COX-2 inhibition as well as several other relevant mechanisms such as NF-κB signalling, phosphorylation of ERK1/2, p38 and/or Akt, activation of PPARγ pathway, suppressing iNOS transcription. The authors finally pointed out to the need to develop new anti-inflammatory molecules from natural sources [10]. The paper by Giuseppina Lagana et al., discusses the most recent developments in the design and development of inhibitors of lactate dehydrogenase (LDH), an enzyme found in all living organisms, which functions for glucose restoration during gluconeogenesis. The text by the authors firstly gives a brief introduction to structural characteristics of LDH along with its isozymes and their physiological role in human metabolism related to cellular homeostasis of redox balance, pH regulation, and signal cascade modulation. Then, they deliberate Nhydroxyindole- based, azole-based, quinoline-derivative, oxamate-derivative, and bifunctional inhibitors as well as galloflavin as a promising inhibitor of LDH in particular, where molecular interactions between the enzyme and inhibitors were mentioned. In conclusion, they brought out attention to finding new LDH inhibitors of synthetic or natural origin considering their therapeutic importance [11]. The paper by Seyed Mohammad Nabavi et al. gives an outline on the role of aporphines in Alzheimer’s disease (AD). The paper firstly introduces AD with its pathophysiological mechanisms; e.g. the formation of β-amyloid plaques and neurofibrillary tangles (NFT), in particular. Then, the authors described some treatment options towards AD such as acetylcholinesterase (AChE) inhibitors obtained from alkaloids of aporphine group. The paper explains how aporphine-derivative drugs in alkaloid form used against AD can act through ChE inhibition and some other mechanisms. For instance, nuciferine as an alkaloid with aporphine skeleton has been proven to be a quite promising ChE inhibitor. On the other hand, oxoisoaporphines, the synthesized alkaloids, were shown to inhibit ChE as well as Aβ self-induced aggregation. In fact, protoberberine alkaloids were revealed to exert a strong inhibition against ChEs. Many of the isolated aporphines from various herbal sources seem to be a remarkable anti-Alzheimer effect. Finally, the authors came to a conclusion that aporphine-type of alkaloids isolated from plants as well as their synthetic counterparts could bear a future potential to become novel anti-AD drug candidates due to their low cytotoxicity and high bioavailability in the organism via its high solubility in an aqueous medium [12]. The paper by H. Ozan Gulcan et al. gives a short introduction to Alzheimer’s disease (AD) and treatment strategies along with an overview of benzimidazole derivatives as drugs. After that, the authors describe benzimidazole derivatives designed for the treatment of AD via different mechanisms for various targets such as the inhibition of amyloid-β1-42, amyloid precursor protein (APP) through the catalytic functions of ß- (also referred to as BACE), and γ-secretase enzymes as well as the prevention of β-amyloid plaques and neurofibrillary tangles (NFT). In addition, many benzimidazole derivatives have been shown to act as H3 (histamine 3) receptor antagonists, gamma aminobutyric acid (GABA)-A receptor modulators, glutaminyl cyclase inhibitors, and peroxisome proliferator-activated receptor (PPAR) modulators. They also discussed some structure-activity relationships between cholinesterase and β/γ-secretase (BACE) enzymes and these compounds, while their efficacy through Tau-protein aggregation and NFT. In the paper, H3 antagonism and (GABA)-A receptor modulation have also been mentioned as one of the mechanisms of action for benzimidazole derivatives towards AD. Glutaminyl cyclase inhibition and PPAR (peroxisome proliferator-activated receptors) modulation were other mechanisms proposed by the authors for the efficacy of benzimidazoles in AD. In conclusion, the authors underlined that the molecules with a benzimidazole ring could be a new target for drug design against AD [13]. The paper by Marco Bonesi et al. gives an extensive overview of inhibitors of tyrosinase (TYR), which are responsible for enzymatic browning in fruits and fungi as well as hyperpigmentation and melanoma, from herbal sources including such plant families as Anacardiaceae, Araceae, Arecaceae, Asteraceae, Cannabaceae, Celastraceae, Convolvulaceae, Ephedraceae, Euphorbiaceae, Fabaceae, Lamiaceae, Orchidaceae, Solanaceae, etc. Besides, active tyrosinase-inhibiting natural molecules, i.e. liquiritin, pinocembrin, eriodictyol, norartocarpetin, and some ginsenosides, (-)-7,8-dihydroxycalamenal, etc. have been also discussed in this text. They also mentioned why inhibition of TYR for in vitro and in vivo anti-melanogenesis particularly by plant extracts and plant-originated molecules is necessary. In this review, polyphenols, particularly flavonoids (e.g. liquiritin, pinocembrin, norartocarpetin, resveratrol), some ginsenosides from Panax ginseng, several phenolic acids such as benzoic acid and orcinol, iridoid glycosides (e.g. iridoid glycosides melittoside, 5-allosyloxy-aucubin), and sesamol, along with several terpenoids including (-)-7,8-dihydroxycalamenal come into prominence. The authors concluded that the discovery of novel TYR inhibitors from plants is a highly attractive option, whereas toxicity studies for short- and long-term effects, as well as pharmacokinetic and pharmacodynamic studies on these inhibitory compounds, are still needed [14]. In conclusion, in the existing special issue of Current Medicinal Chemistry, 6 review articles from eminent scientists highlighting important enzyme inhibitors related to critical diseases of CNS will be published. The special issue covers the most recent concept of conventional and/or natural inhibitors of matrix metalloproteinases (MMPs), cyclooxygenase-2 (COX-2) inhibitors, lactate dehydrogenase (LDH) inhibitors, and aporphines as attractive target molecules for Alzheimer’s disease (AD), and benzimidazole-derived compounds as cholinesterase (ChE) inhibitors and preventers of β-amyloid plaques and neurofibrillary tangles (NFT) towards AD, along with natural tyrosinase (TYR) inhibitors as active anti-melanogenic agents as introduced above, which will shift researchers’ attention to the importance of enzyme inhibition as a popular target for treatment of many diseases once more. I am grateful to Prof. Atta-ur-Rahman, the Editor of Current Medicinal Chemistry, who devoted this special issue to me. I would also like to take this opportunity to acknowledge all the authors for their valuable contributions.

Tumor immunotherapy has entered a phase of rapid development, based on the understanding that the immune system is the best tool humans have for fighting cancer by recognizing and eliminating malignant cells.Treatment with engineered CAR T cells, checkpoint antagonists including anti-cytotoxic T lymphocyte antigen-4 (anti–CTLA- 4), anti-programmed death-receptor 1 (anti–PD-1), and anti-PD ligand-1 (anti–PD-L1), has induced striking responses in subsets of patients with a range of solid tumors. With the FDA approval of sipuleucel-T, ipilimumab (anti–CTLA-4; Bristol-Myers Squibb), and the two anti–PD-1 antibodies, pembrolizumab (formerly MK-3475 or lambrolizumab; Merck) and nivolumab (Bristol-Myers Squibb), immunotherapy has become a mainstream treatment option for some cancers. Such clinical advances also promote massive interest in the search for novel immunotherapy targets, and to understand the mechanism of action of current drugs.Despite the new treatment having shown unprecedented rates of durable clinical responses, with an activity range from 10% to 45% in the context of unselected populations affected by advanced solid tumors,many other patients with solid cancer resistant to immunotherapy such as colon, ovary, and pancreatic cancer have yet to benefit from the innovative therapeutic approaches. Further advances in the effectiveness of cancer immunotherapies will require targeting antitumor immune response at multiple levels, which may be accomplished through combination approaches involving the use of various therapeutic agents to modulate sensitivity to immunotherapy. The review by Zhao and Zhang [1] provides an extensive literature survey of recent advances in the understanding of how HDAC inhibitors alter immune process and discussed their effects on various cytokines. The authors also review the challenges in optimizing the use of these inhibitors as immune modulators in cancer treatment, which may be helpful for designing tumor immunotherapy trials involving HDAC inhibitors.In their overview of basic principles of immune checkpoint inhibitors in both antibody and small-molecule forms. Bin Li et al. [2] discuss potential mechanisms of resistance, which may shed light on further investigation to achieve higher clinical efficacy for immune check point inhibitors. In the next article, Zhou et al. [3] summarize recent progress on targeting CXCL12/CXCR4 axis because of its critical roles in tumor initiation and progression by activating multiple signaling pathways, as well as regulating cancer stem cells. They review the potential utility of targeting CXCL12/CXCR4 axis in combination of immunotherapy and/or chemotherapy based on up-to-date literature and ongoing research progress. From a unique perspective of natural herbal products, Patanaponpibul and Chen [4] review possible immune modulations of various herbal medicines and extracts. The review also provides a useful table listing the origin of species, key chemical components, and clinical studies of these herbal medicines and edible mushrooms. In a systematic review of efficacy and safety of adoptive immunotherapy for B-cell malignancies using CD19- targeted chimeric antigen receptor T-cells, Hao et al. [5] perform a meta-analysis to evaluate the efficacy and side effects of CAR-T on relapsedB-cell malignancies, including leukemia and lymphoma. The review concludes that CD19-targeted CAR-T is an effective modality in treating refractory B-cell malignancies including acute and chronic lymphatic leukemia, Hodjkin’s and non-Hodjkin’s lymphoma. In the present special issue for cancer immunotherapy and immunomodulation, we highlight the current representative progress and encouraging developments in cancer immunotherapy and immunomodulation, with an aim to discuss the challenges and to provide future perspectives on how to exploit a variety of new immunotherapeutic approaches for the treatment of all kind of tumor patients. Future strategies will continue focusing on investigating the complex interplay between targeted agents and immunotherapy and optimizing parameters, exploring different clinical settings and combinations of immunotherapy and chemo or radiotherapy to boost immune response and improve patients outcomes, as well as developing the next generation of predictive biomarkers for immunotherapy.

With the prolongation in life expectancy, a continuously-ageing population is more prone to developing chronic diseases, mainly cancer, cardiovascular, neurologic and inflammatory diseases. The prevalence of such conditions is always increasing, and there is an unmet need for life-saving treatments. Basic and clinical research are upfront in the quest for novel therapeutic strategies to fight such diseases. A growing number of therapeutic targets are being studied for the treatment of chronic diseases. In this mini-thematic issue, we aim at updating the readers of CMC with major advancements in therapeutic strategies for the treatment of chronic diseases.

Metalloenzymes are key enzymes involved in a number of crucial physiological processes. Thus, the dysregulation of metalloenzymes activity is a widespread and pivotal event associated with the onset of the most common diseases of our age, including cancer, rheumatoid arthritis, atherosclerosis, nephritis, neurodegenerative diseases and dry eyes syndrome. In recent years, research on the life sciences has considerably attracted scientists to investigate metalloenzymes and their modulators to meet the challenges of improving human health by discovering new therapeutic targets. In this regard, the fine-tuning of new technologies has allowed the scientific community to better define the structure of the catalytic sites of some metalloenzymes and the role played by the metal. Relying on this information, high affinity inhibitors/ligands, able to modulate the activity of these enzymes, have been successfully identified. Due to the key role of these enzymes in the pathophysiology and pathogenesis of a variety of human disorders, a special issue entitled: Metalloenzymes as therapeutic targets is proposed. Here an interdisciplinary group of scientists (including chemists, biochemists, biologists, pharmacologist, crystallographers, pharmacists and clinicians), which are widely recognized as experts in their research field, have presented, in ten comprehensive review papers, a detailed overview about the most relevant and recent advancements in this field. F. Carta & C. Supuran et al.[1], reported a detailed overview on the most effective modulators of Carbonic Anhydrases (CAs) Metalloenzymes. This review paper provides valuable insights on the key interactions involved in CAs inhibition/activation and the mechanistic details have been highlighted. A clear and updated picture of the structure-activity relationships among the most prominent modulators is provided. M. Ciubotaru et al. [2], deal with the issue related to high level of mutagenesis associated to HIV enzymes and the implication in the discovery of efficient HIV inhibitors. An overview about HIV-integrase structure and functional activity and on the most representative inhibitors is reported. This brings the reader to an easier understanding of the relevance of the ‘Multiple microdomain targeted docking’ as emerging and efficient strategy in HIV integrase inhibitors discovery. The contribution of P. Colinas et al. [3], is focused on a peculiar and less explored cohort of CAs inhibitors. In particular, they described the influence of the conjugated C-glycosides as hydrophilic ‘tail’ on selected CAs inhibitors, on the inhibition selectivity and binding affinity. C. Luchinat & M. Fragai et al. [4], reported a comprehensive overview on the most relevant and recent structural and mechanistic insights on Matrix metalloproteinases (MMPs). Special focus is dedicated on collagenolysis and elastolysis where structural information at the atomic details is described. Moreover, the lastest progress on the development of MMPs inhibitors has been reported. The contribution of R. Honkanen et al. [5], is focused on PPP-family phosphatases (PPPase) providing in-depth insights on the catalytic mechanisms based on relevant biochemical and structural studies. This review starts with a detailed description of diverse PPPase types, moving to the architecture of the phosphatase domain, to the catalytic mechanism. Many PPP-family phosphatases retain a high degree of similarity and make difficult the identification of selective inhibitors. A picture on the structural diversity of phosphatases inhibitors is reported. The aim of the review paper of E. Nuti et al. [6], is to give a systematic overview on the most recent advancements on ADAMs and in particular, on the biological outcomes of the related sheddase activity. Special focus is dedicated to ADAM8, ADAM10 and ADAM17 and on the tuning of their enzymatic activity by using synthetic inhibitors. R. Žalubovskis & J.-Y. Winum [7] contributed a detailed review on inhibitors of four clinically relevant bacterial metalloenzymes, namely peptide deformylase (PDF), metallo-β-lactamase (MBL), methionine aminopeptidase (MetAP) and UDP-3-O-acyl-N-acetylglucosamine deacetylase (LpxC). The review gives an overview on inhibitors-enzyme interaction mechanisms as well as development of novel inhibitors as potent anti-bacterial agents. The review includes also details on clinical development of most successful examples as novel antibiotics. Georgiadis D. and Stratikos E. et al. [8] review the latest developments in the discovery of inhibitors of two enzymes, ERAP1 and ERAP2 which are emerging tractable targets for the regulation of immune responses, with possible applications in the treatment for a broad spectrum of diseases ranging from cancer to inflammatory autoimmune disease. The potential and limitations of these inhibitors for clinical applications is also discussed. The latest findings on the structure-activity relationship of the heme domain of the soluble guanylate cyclase and its bacterial homologues is reviewed by S. Topouzis et al. [9] An overview of the structural properties of these domains is provided in a thorough and comprehensive way. Furthermore, it is given a detailed review of the chemical and structural properties of the "activators" and "stimulators of the sGC as well as their pharmacological profile. Bertrand, P.’ et al. [10] review paper deals with the topic related to post-translational modifications (PTMs) and, in particular, it is focused on metalloenzymes that regulate these crucial processes. A detailed and comprehensive presentation of zinc-dependent histone deacetylases (HDACs), the iron-dependent lysine demethylases of the Jumonji family (JMJor KDM), and, for DNA, the iron-dependent ten-eleven-translocation enzymes (TET) responsible for the oxidation of methylcytosine prior to the demethylation of DNA is reported. Structural and catalytic details, together with a report on the pathologies involving each of these enzymes, and an update on the most relevant modulators of the enzymatic activity give a clear picture of the state of the art in this relevant research field.

Lignocellulosic biomass, such as wood, grasses, and agricultural residues, is a natural composite of cellulose, hemicelluloses, lignin and extractives/natural compounds, and has been recognized as the most abundant renewable resource. Lignocellulosic biomass is one of the most ancient materials that have been industrially utilized and such practices are continued in the modern society. Lignocellulosics are also rich sources for natural ingredients that are essential for the traditional medicine, and have been playing an increasingly important role in medicine/drug development. These subject matters, along with their chemical and pharmacological challenges are still receiving much attention in the research community. The present special issue describes a series of the latest exciting research in the field of medicinal application from lignocellulosic biomass, which covers 1) the development of extraction, separation, purification, activity evaluation processes; 2) structure identification and modification of extractives, cellulose, hemicellulose and lignin to be used for medicine/drug applications; 3) designing and construction of novel drug deliveries based on biobased materials, among others. All these contributions, which take into account the medical applications of the above topics, are summarized as follows. In the paper by Dai and Si [1], an account of the major new findings on the cellulose-based nano-drug delivery systems (nano-DDS) is given. Although cellulose has its own advantages, the structure of pure cellulose has some inherent drawbacks. Herein, various types of cellulose-based nano-DDS employed for the functionalization, pharmacodynamic actions and applications have been covered, including prodrugs, prodrug nanoparticles (NPs), solid NPs, amphiphilic NPs, and polyelectrolyte complex NPs. These interesting research works put forward many strategies for overcoming the free drug molecule shortcomings like poor solubility, suboptimal pharmacokinetics or excess toxicity. Among all the methods described in this review, cellulose-based amphiphilic NPs (including cellulose- lipophilic drug NPs) are most frequently used for constructing cellulose-based nano-DDS. However, the studies on cellulose-based nano-DDS are not without problems, such as the lack of thorough physicochemical characterization and profound understanding of interactions of the nano-DDS with cells in vitro and in vivo, optimization of process parameters and scale up from the laboratory to production level. Along this line, in the paper by Liu and co-workers [2], the role of hemicellulose in medical and pharmaceutical application is addressed. In this contribution, the focus is on the introduction of isolated hemicellulose from plant biomass, degraded hemicellulose, hemicellulose derivatives and hemicellulose-based materials. The effects are depicted on the immune regulation and anti-microbial of nature hemicellulose including xylan, mannan, xyloglucan and β-glucan. The hemicellulose degraded products such as xylo-oligosaccharides, xylitol, xylose, arabinose, mannose and manno-oligosaccharides have some excellent properties for improving the body functions. The modifications of hemicellulose containing esterification and etherification can broaden the medical application in anticoagulant, scaffold materials and anti-tumor. They also present the advantages of hemicellulose-based hydrogels and hemicellulose-macromolecule composites materials on drug delivery and wound dressings. In the contribution by Zhang et al. [3], lignocellulosic biomass materials and their chemical constituents are highlighted as the potential alternatives for the applications in biomedical. In this context, the pretreatment methods for extracting cellulose, hemicellulose and lignin from lignocellulosic biomass by means of milling, irradiation, microwave, steam explosion, ammonia fiber explosion, supercritical CO2, alkaline hydrolysis, liquid hot-water pretreatment, oxidation, dilute- and concentrated- acid hydrolyses and biological pretreatments, as well as their biological applications in the form of hydrogel and membranes, such as drug delivery, biosensor, tissue engineering etc. are summarized. As natural, abundant and renewable resources, the materials derived from lignocellulosic biomass have great potential to be explored for biological applications. In particular, cellulose, as the most abundant natural polymer on earth, is given special focus on the recent development of cellulose-derivatives in drug delivery systems. The authors review the different forms of polymeric systems based on cellulose for drug delivery, such as hydrogels, membranes, microcapsules and nanoparticles. The review by Zhang and Too [4] discusses the potential of using modern biotechnology, especially tools in genomics, metabolic engineering and synthetic biology, to valorize lignocellulose to produce high value pharmaceuticals. In the past decades, biofuels have been the research hotspot in using lignocellulosic waste which contributes a substantial proportion of the agro-industrial biomass. In the review, they discuss the cutting-edge advances in genomic analysis of natural lignocellulose-degrading organisms (for example, fungi and cellulolytic bacteria) and how these studies inspire the development of next generation of carbohydrate active enzymes (CAZymes) and lignin- degrading enzymes (FOLymes). The authors subsequently review the most frontier studies in metabolic engineering of industrial workhorse’ organisms (Escherichia coli and Saccharomyces cerevisiae) for the biosynthesis of natural products. Coupling the forefront genomic study with achievements in metabolic engineering and synthetic biology, the authors project the future directions of developing consolidated bioprocess to manipulate either single microorganism or microbial consortium for the production of drug compounds directly from lignocellulose. The contribution by Sun et al. [5] takes consideration the applications of cellulose-based materials in sustained drug delivery systems. As a natural polymer, cellulose has unique optical, mechanical, and rheological properties and is easy to be chemically reconfigured. The typical modifications of cellulose are esterification and etherification at its hydroxyl groups, and the oxidation of cellulose chain/surface groups, which will impart hydrophilic and hydrophobic properties to suit for unique applications. Micro- and nano-cellulose, produced via mechanical, chemical, enzymatic treatments, and/or their combinations, possess unique properties. When used in drug delivery system, cellulose and its derivatives can modify the solubility/gelling behavior of drugs, resulting in different mechanisms for controlling the release profiles of drugs. The specific applications of cellulose and its derivatives, both the conventional and innovative ones, in the drug delivery area were critically reviewed, aiming at exploring their potential applicability in the novel formulation of pharmaceutical dosage forms. In the review by Khan and co-authors [6], the suitability and future of chitosan in drug delivery are highlighted with special attention to drug loading and release from chitosan based hydrogels. This work demonstrates that extensive studies on the favorable non-toxicity, biocompatibility, biodegradability, solubility and molecular weight variation have made this polymer an attractive candidate for developing novel drug delivery systems including various advanced therapeutic applications such as gene delivery, DNA based drugs, organ specific drug carrier, cancer drug carrier, etc.

anticancer drugs, antimicrobial drugs, antivirus drugs and others, have been saving thousands of people’s lives all over the world every year. However, several limitations, such as bio-stability, drug resistance, limited blood-brain barrier transport and other factors, have substantially hindered the in vivo efficacy of drugs. In order to bring together more researchers from various fields to solve these problems through multidisciplinary approaches, we launch a special issue in this renowned journal, in which we summarize recent advances in strategies and tools for efficient drug discovery and delivery. Aurora A (AurA) kinase is one of important mitotic proteins playing important roles in many cellular functions. Although there are several inhibitor candidates at different stages of clinical trials, these kinds of inhibitors targeting ATP binding sites often suffer from selectivity problems, thus causing undesirable off-target effects. To solve the selectivity problems linked to ATP binding site inhibitors and increase the drug efficacy, Panicker et al. [1] summarize developments of small molecule inhibitors of AurA targeting non-ATP binding sites as well as their prospect on future therapeutics and tools for more efficient drug discovery. Influenza virus infection causes the death of numerous people every year all over the world. Due to limited efficacy of current influenza vaccines and drug resistance of current small molecule antiviral drugs, it is imperative to develop more efficient antiviral drugs with a new mechanism of action. Therefore, Zhang et al. [2] in this review highlight recent advances on drug discovery and assay developments targeting a new biomarker named influenza virus polymerase complex, and also envision their therapeutic potential. Although Polyethylenimine (PEI) has been widely used as a non-viral gene delivery vector for oligonucleotides delivery, its clinical applications and delivery efficiency were hindered by many factors including high cationic charge, low cell recognition and nonspecific interactions with proteins and non-target cells in the biological fluids, thus leading to lower efficiency for oligonucleotides delivery. To conquer these limitations, Hao et al. [3] summarize different modifications of PEI with optimized parameters of PEI or PEI-based formutations for efficient oligonucleotides delivery. As we know, protein and peptide drugs can be easily degraded in vivo, thus leading to lower drug efficacy or shorter half-life. To achieve better drug efficacy and longer drug sustained-release, new sustained-release systems should be applied. Yang et al. [4] summarize recent materials and methods as well as existing opportunities and challenges to fabricate microspheres for better protein delivery. Due to more and more threats of antibiotic resistance, it is urgent and imperative to develop new strategies to combat bacterial infections. Cai et al. [5] review the relatively new pathways that are related to staphylococcal virulence and introduce high-throughput screening strategies to identify novel anti-virulence inhibitors together with their advantages and disadvantages. These are different from traditional strategies and methods in killing bacteria or inhibiting their growth. Compared to normal peptides with limitation in stability and short half-life in vivo, "γ-AApeptides" showed many advantages in drug discovery. In this review by Nimmagadda et al. [6], they review different examples of γ- AApeptides with great potential in biomedical applications, such as application as potential drug carriers due to good cell permeability, as anti-HIV agents, anti-bacterial agents, anti-cancer agents and also anti-Alzheimer’s Disease agents. With scientific and technological advancements, peptide therapeutics have become more and more important. To help scientists to develop even better peptide drugs, this review by Parthasarathy et al. [7] summarize key methodologies and strategies applied in the development of therapeutic peptide drugs focusing on selected examples of the most recent advances in the relevant fields. Although various types of self-assembled micelles have been used to improve diagnostic and therapeutic efficacy of drugs depending on their types, they sometimes suffer from the limitation of low in vivo bio-stability. To conquer this kind of limitation, Fan et al. [8] summarize different types of chemical reactions as crosslinking strategies for enhanced drug delivery abilities of micelles, and also review recent advances on crosslinking polymeric nanoparticles for cancer therapy. It is of great importance to reduce drug toxicity to normal cells while showing good drug efficacy on cancer cells. Among various types of strategies, stimuli-responsive carriers have become more attractive. To better understand how to design a good stimuli-responsive carrier for controlled intracellular drug release, Sheng et al. [9] summarize recent advances on the development of various types of stimuli-responsive carriers for spatially and temporally controlled release of different drugs responsive to different intracellular stimuli, and emphasize optimization of stimuli-responsive materials in terms of molecular design and formulation to improve the clinical drug efficacy via multi-functionality and multiple stimuli-responsiveness. By compiling these different research summaries above, this special issue focuses on introducing new strategies or methods for efficient identification of better therapeutic molecules (e.g. high-throughput screening), or using novel materials, such as nanomaterials, polymers, peptides or other biomolecules, to improve drug efficacy or drug resistance as well as reduce side effects. It is hoped that this special issue will provide readers from the field of medicinal chemistry with valuable information and useful guidelines for innovative drug discovery and improved drug delivery for better drug efficacy.

A biomarker is a measurable characteristic that indicates normal or pathogenic biological processes, or pharmacological responses to therapeutic intervention. There is a strong clinical need to identify novel biomarkers for diagnosis, prognosis, and treatment of human diseases. This Hot topic thematic issue includes articles addressing a multi-disciplinary approach to the unveiling of several aspects of biomarker development against human pathogeneses. An effort is being made to bring together researchers from different countries and to merge complementary approaches, which range from biophysics and biochemistry to microbiology and animal models. A number of key molecules involved in various human pathogens are discussed in this issue as an opportunity to develop molecular entities of diagnostic and therapeutic interest. In particular, this issue describes potential diagnostic tools for cancer disease as well as for bacterial diseases due to Streptococci, Mycobacteria, Salmonella, Pseudomonas. Described tools include not only proteins, but also lipids and nanomaterials. Tumor markers are used to help detect, diagnose, and monitor the evolution of some types of cancer. Elucidating the mechanisms of recurrence of embryonic signaling pathways in tumorigenesis has led to the discovery of oncofetal players, which have physiological roles during normal development but result aberrantly re-activated in tumors. In this context, we describe the roles of the two recognized as onco-developmental factors, Nodal and Cripto- 1, which are absent in normal tissues but are overexpressed in several solid tumors. Data demonstrate the clear connection between Nodal and Cripto-1 presence and their multiple oncogenic activities across different tumors. Therefore, Nodal and Cripto-1 represent two innovative and effective biomarkers for developing potential theranostic anti-tumor agents to overcome both pharmacological resistance and tumor relapse [1]. Biomarkers are becoming increasingly important tools also in infectious diseases, to distinguish bacterial from nonbacterial infection, to monitor the response to therapy, and to predict therapy outcomes. The cell walls of bacteria bear an arsenal of molecules that elicit host immune responses and may act as biomarkers. Group A Streptococcus (GAS) infections are responsible for significant morbidity and mortality worldwide. At the portal of entry, GAS binds to the newly deposited extracellular matrix, which is rich in cellular fibronectin isoforms with extra domain A via a surface adhesin, the streptococcal collagen-like protein 1 (Scl1) [2-4]. Similarly, Mycobacterium tuberculosis, the etiological agent of Tuberculosis (TB), binds to epithelial cells using the HBHA adhesion [5, 6]. In both cases, these adhesins have been shown to be interesting diagnostic tools. Notably, HBHA was shown to distinguish between an active and a latent state, a reversible low metabolism state of the Mycobacterium, rendering itself extremely resistant to host defense and drug treatment due to modifications of the mycobacterial cell wall [7, 8]. Similarly, other tools to diagnose TB at the latent and active stages and to recognize prospective TB diagnostic methods have been based on lipids and nanomaterials [9,10]. In Gram-negative bacteria, including Salmonella and Pseudomonas aeruginosa, bacterial life activities and interactions with external environments relief on outer membrane proteins (OMPs) and OM-associated proteins [11]. The role of key OMPs involved in Salmonella serum and antibiotics resistance, is described here as an opportunity to develop biomarkers against multi-drug resistant bacteria. P. aeruginosa is of great interest as a model of biofilmforming organism and research in this area has contributed to understand how biofilms are formed and how they can act as biomarkers of disease [12]. Overall, this issue provides complementary views, by experts in the field, of various scenarios of biomarker identification and validation. It is yearned that knowledge of molecular events involved in biomarker recognition will significantly impact the development of diagnostic and therapeutical agents.

Atherosclerosis is driven by lipid accumulation in the arterial wall that leads to narrowing the vessel lumen and increasing risk of thrombus formation. Deposition of lipids, mostly cholesteryl esters, in the arterial wall layer called intima, is one of the earliest manifestations of the disease. Intracellular accumulation of lipids takes place in so called foam cells that have their cytoplasm filled with lipid droplets that are visible microscopically. Circulating low-density lipoprotein (LDL) particles serve as the primary source of lipids. Numerous attempts were made to establish a clear link between circulating LDL levels and atherosclerosis formation. In the experiments conducted on cultured cells, if was demonstrated that native LDL failed to induce intracellular lipid accumulation. At the same time, LDL chemically modified in vitro (acetylated, malondialdehyde-treated, oxidized with ions of transient metals, etc.) induced lipid deposition in cultured cells, i.e., was atherogenic. It was therefore suggested that not native, but modified LDL contributes to lipid deposition leading to atherosclerosis. However, the attempts to find modified LDL in circulation were unsuccessful. That resulted in a paradox that for a long time remained unsolved: (i) LDL is the source of lipids accumulated in the vascular wall; (ii) native LDL does not induce intracellular lipid accumulation (foam cell formation); and (iii) in vitro modified forms of LDL are atherogenic but cannot be found in circulation. To solve this paradox, several research groups began the search for atherogenic modified LDL present in circulation of atherosclerosis patients. LDL can exist in several forms with different physical-chemical properties. Small dense (sd) LDL and electronegative LDL (LDL(-)) are characterized by increased density, decreased size and acquired electric charge. Oxidized LDL (oxLDL) is the product of chemical modification of particles. All these forms of LDL are regarded as pro-atheroginic, the level of high-density lipoprotein (HDL) may have an important protective role serving as cholesterol transporter from the arterial wall to the liver, where it is further metabolized. Numerous studies have demonstrated that low plasma levels of HDL are associated with increased risk of cardiovascular disease. Moreover, experiments on animal models have shown that HDL inhibits lipid oxidation and have beneficial effects improving endothelial function, alleviating inflammation and protecting cells from apoptosis. It was suggested that during local or systemic inflammation, HDL can be converted to a dysfunctional form with decreased anti- atherogenic effect. Dysfunctional HDL can be formed as a result of loss of anti-inflammatory and anti-oxidant proteins possibly combined with up-regulation of pro-inflammatory proteins. In this Thematic issue, we provide an overview of the current knowledge on the roles of dysfunctional or modified HDL and LDL in atherosclerosis pathogenesis. This knowledge may provide an important contribution to the development of novel therapeutical methods to combat atherosclerosis. The first review by Sobenin and Orekhov [1] addresses the mechanistic role of LDL and HDL in atherogenesis. The authors question the widely accepted hypothesis of the central role of oxLDL in atherogenesis while proposing an alternative concept of multiple modification of LDL particles. The authors also address the important question of whether LDL and HDL are biomarkers, effectors, or both in cardiovascular disease. The answer to this question would allow setting priorities for using lipoprotein particles as therapeutic targets or diagnostic tools. The contribution by Arnao and Tuttolomondo [2] takes into consideration the measures of functional features of lipoproteins, instead of conventional routine serum evaluation of lipoproteins, that could offer a valid contribution in experimental studies as in clinical practice to stratify atherosclerotic risk. Along this line, in the review by Chroni and Kardassis [3], it is also claimed that HDL functionality is more important than HDL-cholesterol (HDL-C) levels for cardiovascular risk prediction. Thus, detailed characterization of changes in HDL composition and functions in various pathogenic conditions is critically important in order to identify new biomarkers for diagnosis, prognosis and therapy monitoring of cardiovascular diseases. The authors provide an overview of how HDL composition, size and functionality are affected in patients with monogenic disorders of HDL metabolism due to mutations in the genes that participate in HDL biogenesis and remodeling. The authors also review the findings from various mouse models with genetic disturbances in the HDL biogenesis pathway that have been generated for validation of the data obtained from humans and discuss how these models could be utilized for the evaluation of novel therapeutic strategies such as the use of adenovirus-mediated gene transfer technology that aims to correct HDL abnormalities. Itabe and co-workers [4] discuss the significance of circulating oxLDL in various systemic diseases, including acute myocardial infarction and diabetes mellitus. Several different enzyme- linked immunosorbent assay procedures measuring oxLDL were utilized. Accumulating evidence reveals changes in oxLDL levels under certain pathological conditions. Since oxLDL concentration tends to correlate with LDL-cholesterol, the ratio of oxLDL and LDL rather than oxLDL concentration alone should be considered. In addition to circulating plasma, LDL and oxLDL are found in gingival crevicular fluid (GCF), where the ratio of oxLDL to LDL in GCF is much higher than in plasma. LDL and oxLDL levels in GCF are increased in diabetic and periodontal patients, suggesting that GCF might be useful for examining systemic conditions. GCF oxLDL increased when the teeth were affected by periodontitis. It is likely that oxLDL levels in plasma and GCF could reflect oxidative stress. The paper by Schnitzler and co-authors [5] describes LDL modifications that convey inflammatory and pro-atherogenic effects that affect the endothelial function and promote foam cell formation. Apart from the central role in lipid transport and metabolism, LDL can have direct effects on the composition of circulating monocytes promoting immune cells migration and accumulation in the subendothelial space. Current evidence shows that other lipoprotein particles, including triglyceride(TG)- rich remnants and lipoprotein (a) [Lp(a)] can also influence atherogenesis. For instance, Lp(a) can promote peripheral monocyte activation followed by increased migration of the immune cells through the endothelium. Cholesterol contained in TG-rich remnants can affect endothelial dysfunction and monocyte activity. The paper by Ossoli et al. [6] presents an updated review of pathologic mechanisms, especially those associated with inflammatory signaling, involved in alterations of HDL protein and lipid contents that lead to the formation of dysfunctional HDL; The authors discuss the currently available and investigational drugs that are aimed at normalizing the lipid metabolism and alleviate HDL deficiency and dysfunction. The aim of the paper by Miyazaki and Miyazaki [7] is to contribute to the current debate on the insufficient protein catabolism that affects cholesterol handling by macrophages. Impaired autophagy and clearance of dying cells promotes cholesterol accumulation in the cells which leads to the formation of the most dangerous vulnerable plaques associated with thrombotic events. Proteasome plays a central role in the degradation of ATP-binding cassette transporters affecting cholesterol efflux from macrophages. Next, the authors discuss calpains, overactivation of which can contribute to the excessive degradation of functional proteins that promotes receptor-mediated oxLDL uptake and reduces cholesterol efflux. Calpain-6 is non-proteolytic calpain of macrophages that potentiates pinocytosis, in particular, the uptake of native LDL, and attenuates efferocytic clearance of dying cells. The authors discuss how the defective protein catabolism affects macrophage cholesterol handling and atherogenesis. As in the first reviews of this Special Issue [2, 3], the review by Pirillo and co-workers [8] states that focus should be shifted from HDL-C levels toward HDL functional properties. The authors note that dysfunctional HDL extracted from the plasma of atherosclerotic patients has both impaired atheroprotective functions and marked proatherogenic properties. Dysfunctional HDL can be defected even in the presence of normal or elevated HDC-C levels. Therefore, drugs that allow restoring of HDL functions may have a more potent role in treatment of cardiovascular diseases than therapies that simply increase HDL-C level. The authors discuss the mechanisms of dysfunctional HDL formation and their role in atherogenesis and beyond. The paper by Rivas-Urbina with co-authors [9] is focused on LDL(-), which is known to have certain proatherogenic properties. Electronegative LDL is a heterogeneous LDL fraction that can be isolated on the basis of the negative electric change by physical methods. It probably has different biochemical origins, but in general is known to be atherogenic. However, in some cases, LDL(-) can have anti-atherogenic properties. Several molecular modifications leading to LDL(-) formation have been described, but their relationship with the pathology development remains to be studied in detail. The authors discuss the recent advances on the studies focusing on LDL(-) biology and relationship with cardiovascular risk. They highlight the importance of minor lipoproteins associated with LDL(-) that may play a crucial role in modified LDL properties. The paper by Lopes-Virella and Virella [10] is dedicated to the antigen-antibody complexes (immune complexes, IC). IC that are recognized primarily by copper oxLDL antibodies were isolated from patients with progressive atherosclerosis measured by intima-media thickness (IMT) and increased coronary calcification scores. At the same time, patients who had ICs reacting with antibodies to the heavily oxidized malondialdehyde LDL prepared in vitro (MDA-LDL) had increased risk of acute vascular events, in particular, myocardial infarction. As demonstrated in in vitro studies, oxLDL IC induce both cell proliferation and mild to moderate macrophage apoptosis, while MDA-LDL IC induce a more marked macrophage apoptosis but not cell proliferation. Moreover, MDA-LDL IC induce the release of higher levels of matrix metalloproteinases and TNF than oxLDL IC. These factors play a prominent role in apoptosis promoting thinning of the fibrous cap leading to the formation of vulnerable plaques and therefore increasing the risk of acute cardiovascular events. Kattoora and co-workers [11] consider the LOX-1, a transmembrane glycoprotein, as a receptor for oxLDL, modified lipoproteins, activated platelets and advanced glycation end-products. LOX-1 is expressed on macrophages, where it inhibits the immune cell migration. In atherosclerosis, this molecule plays a role in promoting foam cell formation and vulnerable plaque formation by stimulating the generation of metalloproteinases. LOX-1 mediates the effect of oxLDL on the endothelial cells, causing up-regulation of leukocyte adhesion molecules, activating apoptosis, increasing the production of reactive oxygen species and causing endothelial dysfunction. This signaling pathway stimulates vascular smooth muscular cells to proliferation, migration and collagen synthesis. LOX-1- targeting drugs may therefore have a great potential for atherosclerosis treatment. Many naturally occurring compounds have been shown to modulate LOX-1 expression and have an effect on atherosclerosis. Current efforts are focused on identifying molecules that can bind to LOX-1 and inhibit its activation by oxLDL. Other approaches include RNA interference techniques and monoclonal antibodies binding LOX-1. Öörnia et al. [12] discuss the findings of recent observational and genetic studies that have discovered that the TG-rich lipoproteins and their remnants are linked with cardiovascular disease risk. The authors describe the potential mechanisms by which the TG-rich remnant lipoproteins can contribute to the development of atherosclerotic lesions and highlight the differences in the atherogenicity between LDL and the remnant lipoproteins. We hope that this Special Issue will be of interest to the readers and will contribute to the growing knowledge on lipoprotein biology and its involvement in atherosclerosis pathogenesis.

Activatable theranostics are novel clinical solutions, combining diagnostics and therapeutics moieties, for early diagnosis, monitoring, and prognosis of diseases. This thematic issue compiles 7 review articles including a series of latest advances in the field of activatable theranostic platforms for different diseases such as cancer, diabetes, neural diseases, and so on. For cancer theranostics, G. Liu and coworkers [1] summarized recent research progresses related to green synthesized nanoparticles for cancer theranostic applications, elucidating the current challenges and insight into the future directions in these areas. W.-G. Zhu and coworkers [2] summarized the important roles of epigenetics, especially histone modifications in cancer diagnostics and therapeutics, and also discussed the developmental implications of activatable epigenetic targets in cancer theranostics. Y. Gao and coworkers [3] provided insights into the strategy using enzyme instructed self-assembly in biological milieu for theranostics purpose. Meanwhile, D. Ling and coworkers [4] summarized recent advances of stimuli-responsive organic-inorganic hybrid nanogels for activatable theranostics. For drug delivery and diagnosis, Z. Gu and coworkers [5] summarized recent advances of cysteine-rich proteinbased biomedical materials and their applications in tumor-targeted drug delivery and diagnostics. K. Pu and coworkers [6] reviewed recent progress of organic nanomaterials including near-infrared dyes and semiconducting polymer nanoparticles in photoacoustic imaging-guided cancer phototherapy, and also addressed their challenges and potential in clinical applications. T. Wang, P. Huang and coworkers [7] introduced the development of phototriggered drug delivery systems in neuroscience research and their neuron-related applications including regulating neural activities, treating neural diseases and inducing nerve regenerations. By compiling these papers, we hope to enrich our readers and researchers with respect to activatable theranostics.

The ATP-binding cassette (ABC) transporters belong to a superfamily of export pumps. They are expressed in many tissues at variable membrane domains, and recognize as substrates a wide spectrum of therapeutic agents. Placed in strategic epithelia such as liver, intestine and kidneys, together with biotransformation systems and other membrane transporters, they constitute an important regulator of drug absorption, pharmacokinetics and therapeutic efficacy. ABC transporters also play a role in elimination of potentially toxic derivatives of endogenous compounds. In this special issue, we provide updated information starting from basic concepts related to their mechanism of function to strategies for manipulation of their activities with therapeutic purpose. To begin this series, Arana and Altenberg introduce ABC transporters and describe their classification in subfamilies according to common structures [1]. They provide, in a comprehensive way, explanation for the mechanism of transport. Reference about correlation between recently acquired structural information and function is also made, including the molecular mechanisms involved, with particular emphasis in participation of nucleotidebinding domains. Comparison of the structures of two important members of the ABC family, P-glycoprotein (P-gp, MDR1) and Multidrug resistant-associated protein 1 (MRP1) provides important clues for our understanding of their function. The activity of ABC transporters is not static but rather subjected to a dynamic modulation through transcriptional, post-transcriptional and post-translational regulations. Rigalli et al. compiled information about transporter regulation by nuclear receptors, mainly involving transcriptional mechanisms [2]. Updated information links receptors activation (or inhibition) with modulation of ABC transporters and, this way, with a desired pharmacological effect. Main receptors considered in this review are xenobiotic receptors, bile acid and lipid receptors and retinoid receptors. Transport activity can be regulated also at post-translational level in an acute manner, as a consequence of changes in transporter localization. An extensive description of this mechanism is presented by Roma et al. with hepatic canalicular transporters being selected examples [3]. These transporters are localized either in the plasma membrane domain or in an endosomal, recycling compartment, and the balance between these localizations determines the capability to express transport activity, ultimately conditioning bile formation and elimination of endoand xenobiotics. The possible mechanisms explaining such regulation are also well described in the review. Regulation of expression and activity of ABC transporters were also well characterized in extrahepatic tissues. Villanueva et al. present an extensive description of function and regulation of ABC transporters in heart and small intestine, as examples of extrahepatic tissues, in which ABC proteins play clearly different roles [4]. In heart, they are involved in tissue pathogenesis as well as in protecting this organ against toxic compounds and drug-induced oxidative stress. In small intestine, they strongly influence absorption and pharmacokinetics of drugs incorporated orally. While a significant function of ABC transporters in polarized epithelia is related to the apical secretion of substrates contributing to their elimination from the body, several family members are located in the basolateral membrane and play a different role. In the review by Ghanem and Manautou, detailed information is provided on studies examining the changes in expression and regulation of the basolateral hepatic transporter MPR3 by xenobiotics and by different pathophysiological conditions [5]. The authors emphasize the consequences of such changes in the pharmacokinetic, pharmacodynamic and toxicity of different drugs of clinical use. Development of multidrug resistance (MDR) leads to chemotherapy failure generally associated with overexpression of ABC transporters such as P-gp, several members of the MRP subfamily, and breast cancer resistance protein (BCRP). Ceballos et al. compiled information about transcriptional and post-transcriptional regulation of ABC transporters and discussed their role in the development of MDR in cancer cells [6]. They particularly focus on drug resistance exerted by ABC efflux transporters in hepatocellular carcinoma and colorectal carcinoma. The authors also discuss aspects of the chemotherapy failure and future directions to overcome MDR. Unlike physicians, veterinary practitioners deal with different animal species with crucial differences in anatomy, physiology and metabolism, so that pharmacokinetics, clinical efficacy and adverse effects of drugs may also be different. Moreover, the use of drugs in food-producing species constitutes a risk for humans due to the generation of chemical residues in edible products. Virkel et al. review the information available on major ABC transporters which affect the disposition of drugs used to treat livestock and domestic animals [7]. Investigations reveal the major relevance for P-gp, BCRP and different MRP members in both companion and livestock animals. While studies on basic aspects of ABC transporters structure, expression and function are largely available, not much can be found in the literature on targeting ABC transporters with therapeutic intention. MRPs have been linked to several diseases and have been proposed as promising therapeutic targets, e.g. by using selective inhibitors. To reduce the adverse effects of candidate inhibitors, it is necessary to revise the structure of the target proteins and at the same time to particularly consider their physiological functions. In the review by Yaneff et al., both aspects are thoroughly studied using MRP4 as example [8]. The authors evaluate homology models together with mutagenesis assays, and carefully scanned MRP4 structural characteristics and compared them with other MRP family members. They postulate several candidate residues consistent with highly probable cAMP binding sites that may serve as a basis for the future development of inhibitors of MRP4-mediated cAMP transport.

The constant improvement in technology and in the comprehension of molecular biology has allowed to conceive a series of biological treatments of cancer and of many inflammatory and chronic degenerative diseases. These treatments are usually less invasive than pharmacological ones and in many cases can be used in a concomitant way with the canonical treatments so that it is now possible to draw up new guidelines for integrated treatments related to human chronic diseases. This special issue, devoted to " New Insights into the Complexity of Cancer and of Inflammatory Diseases” certainly moves within this direction and collects a series of reviews-articles which strictly reflects the recent advances. Many articles are focused on treatment or prevention of cancer. One article by Nicolini A. et al. [1] describes breast cancer treatments with the use of an innovative and more general biological or immunological approach while another by Antonelli et al. [2] regards the use of sunitinib in thyroid cancer patients. This is quite interesting issue being a so called "target therapy" so far usually investigated in other types of cancers. However its efficacy in thyroid cancer patients no more responsive to radio-iodine is currently under evaluation. The third article by Cullen et al. [3] describes the role of some important biological substances used as integrative treatments of many cancer diseases, whereas the fourth by Biava et al. [4] describes how it is possible to reprogram cancer cells to a healthy phenotype. The model presented in that article is a quantum field theory model in which the factors taken during the stages of cell differentiation are able to trigger symmetry breakdown processes during cancer development. The model is consistent with the real situation and especially it applies to the reverting process of cancer cells to a healthy phenotype. It provides a possible understanding of how we can achieve such a result and reprogram cancer cells. The fifth article by Klener et al. [5] is a review about the biological treatments in hematologic malignancies, while the review-article by Pavelka et al. [6] about the inflammatory and degenerative diseases regards the chronic low back pain and the most important pharmacological therapies in this disabling condition. In the seventh article by Pistello et al. [7] the role of virome in modulating inflammation in cancer and various degenerative diseases is illustrated and strong evidences that anelloviruses are useful and practical molecular markers to monitor inflammatory processes and immune system competence also is provided. The last review article by Anceschi et al. [8] represents an updating about the biomarkers related to prostate cancer and describes the old and new biomarkers of this kinds of tumor.

Atrial fibrillation (AF) is a frequent cardiovascular entity (almost 33 million subjects worldwide suffering from different forms of this entity) especially in developed countries [1] accompanied by poor quality of life and posing significant morbidity and mortality which may explain the increasing amount of research on ion and cells mechanisms, the identification of electric circuits and the introduction of novel pharmaceutical and invasive strategies. Despite the advancements in diagnostic strategies, the recognition of the multiple wavelet hypothesis and rotors as sources of AF, the introduction of invasive strategies targeting specifically the generation of AF and the introduction of improve anticoagulant strategies we are far away from a treatment highly efficient since the best results for example of AF ablation reach only 60-70% success rate [2]. Therefore, there are gaps in evidence such as the basic pathophysiologic mechanisms underlining ion channels alterations, re-entry circuits and electrical remodeling, the identification of the patients best responsible to atrial fibrillation ablation, the selection of the optimum anti-arrhythmic management in each case and risk categorization of the patients concerning stroke risk, bleeding risk and recurrence of atrial fibrillation. As the role of biomarker in the research relative to AF initiation and progression and in the management of clinical AF episodes is limited we believe that further insights into the role of specific biomarkers can be proved usefully in the understanding and management of this entity. In this thematic issue, we will discuss the role of biomarkers in the pathophysiology of AF, in prognosis, in the risk stratification for stroke and bleeding and in treatment strategies and in specific comorbidities associated with AF. This special issue contains 13 review articles. The first 4 articles focus on the underlying pathophysiologic mechanism of AF [3-6]. The following 4 reviews present the possible role of biomarkers under specific circumstances [7-10]. Finally the prognostic role of biomarkers is presented in the last 5 articles [11-15]. All these issues are supported by appropriate illustrations and tables. The role of inflammation in several cardiovascular diseases has been revealed over 3 decades ago which continues to focus interest since the modification of inflammatory cataract appeals as an attractive alternative therapeutic approach. The association of inflammation with AF seems to be bidirectional (AF may initiate the inflammatory cataract and a pro-inflammatory status precipitates episodes of AF). The purpose of the first article [3] is to examine this association and present data how biomarkers such as C reactive protein, Interleukin-1 and tumor necrosis factor are implicated in the genesis and perpetuation of AF. Redox stress has been revealed as a significant factor affecting not only atherosclerosis progression and heart failure but several comorbidities. Formation of superoxide, hydroxyl radicals and peroxynitrate may cause oxidative modification of proteins and mitochondrial DNA damage, leading to cellular death and altered ion channels function. Under these circumstances, electrical properties of myocardial cells are modified and oxidative stress is implicated in the genesis of AF as it is presented in the second review of this issue [4]. The role of atrial fibrosis and remodeling has for long been recognized as a pathophysiologic mechanism of AF. Dilaveris et al. [5] focus on the underlying mechanisms of extracellular remodeling and present useful data how biomarkers can be used to monitor and evaluate the extent of remodeling and the prognostic yield of these biomarkers in the treatment strategies. The role of small non-coding RNAs (microRNAs) has been recently revealed. They can orchestrate many biologic processes and organ functions. Their role in cardiovascular system focus is on the research interest in the setting of AF specific MicroRNAs as presented by Briasoulis et al. [6] which can not only be used to further understand pathophysiologic mechanisms but also to identify subjects prone to develop AF. Atrial fibrillation is associated with several comorbidities. The specific issues raised when AF coexist with aortic stenosis, heart failure, hypertension and metabolic syndrome which are examined in the following 4 review articles. Toutouzas et al. [7] give insights in the interaction between AF and aortic valve stenosis and focus on the biomarkers that can be used to determine the prognosis of arrhythmias in patients after transcatheter aortic valve implantation. The close interrelationship between AF and heart failure is well established. In the following review [8], the significant role of a set of biomarkers in the prognosis of HF and atrial fibrillation is presented and the article focuses on the mechanistic links between raised natriuretic peptides and altered myocardial cell electrical properties which may precipitate in the episodes of AF. The prevalence of AF is increased in patients with hypertension and may further deteriorate patients’ functional status or may lead to clinical evident heart failure. Tsioufis et al. [9] present the biomarkers involved in the atria electrical remodeling in patients with hypertension and they propose a combination of multiple indices to effectively detect both AF and adverse characteristics of high risk patients with hypertension. Metabolic syndrome is an entity that encompasses a cluster of derangements such as obesity, hypertension, diabetes mellitus and dyslipidemia which may further deteriorate cardiac function and may adversely impact atrial remodeling and electrophysiologic properties. Vlachopoulos et al. [10] provide the most recent data concerning the link of these entities with the biomarkers associated with maladaptive changes in atrial remodeling. Unfortunately, AF may cause significant complications in morbidity and mortality especially when it causes stroke or hemorrhage. Several prognostic models are used the last years in cardiovascular patients. A series of biomarkers are examined by Mazaris et al. [11] for their effort to support the clinician’s prognostication ability while the additive prognostic value of biomarkers in determining the stroke risk is examined in a review article by Ioannou et al. [12]. In an interesting review, Sideris et al. [13] focus on the prognostic ability of biomarkers in the bleeding risk and how they can be used to altertherapeutic decisions. The last two review articles covered two interesting issues. Development of atrial fibrillation after cardiac surgery may complicate post cardiac surgery period and may need specific treatment. Manfrini et al. [14] focus on the biomarkers which can be used to determine prognosis and identify patients needing preventing strategies. Finally Tsiachris et al. [15] examine how biomarkers can be used in atrial fibrillation ablation. Since results of atrial fibrillation are modest achieving a success rate of 60-70%, the identification of best candidates for this invasive strategy is of importance since it may change treatment decisions. The additive prognostic information obtained by the use of specific biomarkers is examined in this review as well as the role of biomarkers in the monitoring of AF recurrence.

After Rosenberg’s discovery (in the early 1960s) of therapeutic potential of cis-diamminedichloroplatinum(II) (cisplatin), we witnessed a great development of coordination chemistry. Many researchers worked on synthesis, structure and cytotoxic effect of platinum(II) complexes with different ligands, but soon other metal ions and their complexes entered the stage. Nowadays, they are also tested in several other ways as potential drugs in, e.g. neurodegenerative diseases, as well as chemotherapeutic, antimicrobial, and antifungal agents. More specific areas of interest involve metaldrug interaction and metalloproteins as drug targets. These aspects, together with an important role played by transition metals, like iron(II)/(III), copper(II), or zinc(II), constitute a field of intense multidisciplinary studies. Seven reviews collected in this special issue were intended to show results of the research mostly from the biological/medical point of view, with less attention paid to the chemistry. Chapter described by Kiss and co-authors [1] deals with the problems of speciation of metal complexes of medicinal interest: The authors discuss several biologically active metal-ligand families and try to find relationship between solution equilibria of the metal-ligand systems and the pharmaceutical properties of the complexes formed in the systems. Due to various biotransformation reactions the original form of a bioactive molecule is very often differs from the physiologically active form of the drug. For this reason the biospeciation of metal complexes with biological or medicinal activity are discussed in the chapter in order to emphasize the importance of the distribution of metal ions in biological milieu. The exact knowledge of the chemical species present in the different organs/compartments/fluids/cells may provide essential information about the pharmacokinetic properties and the biological effect of the metal ion or the drug candidate metal complex. The transport of essential and toxic metal ions in the blood serum is discussed first, which is followed by the description of biodistribution of several important metal complexes with medicinal interest such as (i) anticancer, (ii) insulin-enhancing and (iii) MRI contrast agents in biological fluids. A chapter by Petanidis et al. [2] entitled ”Tumor cell chemoresistance is a major challenge in cancer therapeutics” presents the molecular immune-related mechanism in the tumor microenvironment, leading to drug resistance. Whereas metal-based drugs are potent anticancer agents, they are often effective against only few types of cancers and cause severe side-effects Therefore new drugs with an improved spectrum of efficacy and lower general toxicity are needed. Their development is stimulated by considerable efforts aimed at elucidation of the mechanisms of action, thus their bioactivity can be optimized through structural modification. In that respect, knowledge on the molecular factors involved in drug resistance and immune response may help to develop new anticancer strategies and new promising chemotherapies, and to reduce the rate of relapse. The important part of this review was the investigation of strategies for reversing drug resistance while concurrently optimization of the design of metal complexes bearing anti-tumor activity, is discussed in an effort to identify and overcome underlying mechanisms of resistance to both standard chemotherapeutic agents and targeted molecular therapies. Hecel et al. [3] discussed the use of silver(I) complexes in medicine and pharmacy. Silver is a non-essential element, although traces of silver salts can be found in various tissues. From a historical perspective, it has been that Ag(I) and its complexes have been used by humans for thousands of years. At present, they are widely used in chemistry and industry, and improper utilization of the silver containing products and wastes poses hazard to health and environment. In medicine, pharmacy and cosmetology, the silver containing compounds are being used for important antibacterial and antifungal properties. The chapter summarizes the latest findings on the bioinorganic chemistry of silver complexes and nanoparticles. The coordination chemistry of silver is given a reasonable amount of attention, summarizing the most common silver binding sites and giving examples of such binding motifs in biologically important proteins. The already developed and future applications of this metal and its complexes in medicine, in particular as antibacterial and antifungal agents and in cancer therapy, are discussed. Malinowska and co-authors [4] described the medical applications of complexes of metal ions with small heterocyclic compounds containing nitrogen atoms within three-or five-membered rings. Such derivatives of pyrazoles, aziridines and diaziridines with metal ions like Cu(II), Zn(II) and Ru(III) exhibit interesting biological activity and their antioxidant, anticancer, anti-inflammatory, immunomodulatory and antimicrobial properties are presented. The authors have collected the results of the studies from the last years that concern antimicrobial and anticancer properties of pyrazoles complexes and the potential application of aziridine-containing natural compounds as chemotherapeutics with anti-cancer, and antimicrobial agents. The article also pointed out the need of conducting of more detailed pharmacological studies on these kind of compounds as in vitro research seems to be interesting but also insufficient. A chapter entitled "Antimicrobial and structural properties of complexes of selected metal ions with thiosemicarbazide and its thiosemicarbazone derivatives" by Namiecinska and myself [5] consists of a chemical and a biological part. The first one shows the synthetic methods and the structures of complexes of metal ions [Cu(II), Cd(II), Pd(II), Ni(II), Ru(II), Zn(II) and Mn(II)] with ligands containing a thiosemicarbazide motif. The second one provides data on antibacterial, antifungal and antiviral activities of those complexes. Thiosemicarbazide and thiosemicarbazones constitute many of the synthesized complexes that possess two important classes of sulphur, nitrogen donor ligands, particularly well interacting with many transition metal ions. The presented properties kindle some hopes for application of these complexes in the combat of infectious diseases, especially those caused by pathogens resistant to antibiotics, including biofilm-type infections. An interesting review “Mitochondria-targeting anticancer metal complexes” has been wrote by Andrea Erxleben [6]. About five years ago, the acronym ‘mitocan’ was coined for ‘mitochondria and cancer’. Mitochondria play a fundamental role in cell death and survival signaling and have become an important target for cancer therapy. In this review, anticancer metal complexes are discussed that exert their cytotoxic activity by damaging the mitochondria or by interacting with mitochondrial proteins. The review starts with a short introduction into mitochondria-mediated pathways of apoptosis and experimental methods to study metal complex uptake of the mitochondria. The three main sections then cover metal complexes that - due to specific carrier ligands or due to their lipophilic cationic nature – accumulate in the mitochondria, metal complexes that damage the mitochondria and metal complexes that interact with mitochondrial thioredoxin reductase and the translocator protein in the outer mitochondrial membrane. The current state of the art in the design, antiproliferative activity and mechanistic understanding of antimitochondrial metallodrugs is described with a focus on metal ions such as Au, Ru, Ir and Pt. The last chapter entitled “Recent Research Trends on Bismuth Compounds in Cancer Chemo and Radiotherapy” has been written by Kowalik and co-authors [7]. For many years bismuth(III) complexes have been widely used in medicine with satisfactory therapeutic effects, mostly in Helicobacter pylori eradication, but also as potential antimicrobial and anti-leishmanial agents. Recently, special attention in the field of coordination chemistry has been continuously focused on medicine based on bismuth(III), containing therapeutic compounds. Therefore, in the first part of this review, the authors would like to characterize not only ligands from such classes as: thiosemicarbazones, hydrazones, and dithiocarbamates, but also anticancer properties of selected bismuth(III) complexes. In the second part of this review, Kowalik will discuss the current knowledge connected with: (1) radiation therapy based on Bi-nanoparticles and nanodots, and (2) targeted radioimmunotherapy based on bismuth(III) radionuclides. In radiotherapy, nanoparticles based on bismuth compounds are primarily utilized as radiosensitizers, to obtain dose enhancement effect of radiationoncology. In turn, 213Bi alpha-radioimmunotherapy represents an emerging therapeutic modality for tumour treatment that is currently under active investigation based on (i) the choice of targeting vector, (ii) the use of proper bifunctional chelator, and (iii) the retention studies of 213Bi as recoiling daughter nuclide of 225Ac. To summarize, this review presents recent research studies on bismuth compounds in cancer chemo- and radiotherapy, suggesting directions for future research. I think that the presented paper will be interesting for the readership of Current Medicinal Chemistry.

Proteins function as the major executors of genetic programs in all living organisms, including humans. However, only a minority of pharmaceuticals available in drugstores contain proteins or peptides as active compounds. This contradiction stems from multiple limitations accompanying the development of pharmacologically active proteins, their production, and pharmacological use. Nonetheless, it is now clear that these limitations can be effectively solved, resulting in an increase of implemented protein-based pharmaceuticals. Furthermore, the initial successes in the field of regenerative medicine point to novel applications for matrix proteins. Therefore, this special issue of Current Medicinal Chemistry entitled “Proteins in Pharmacology: restrictions, challenges and opportunities” has collected recent review papers dedicated to pharmacologically active proteins, their therapeutic applications, recombinant proteins as sources of pharmacologically active compounds (including their expression, purification, refolding and proper posttranslational modifications), antibodies, enzymatic therapy assays, matrix proteins for regenerative medicine, novel molecular targets and more. Pharmaceutical proteins are used for the diagnosis, prevention and treatment of diseases creating a strong demand to produce recombinant proteins on an industrial scale. Many expression platforms including bacteria, yeast, plants, mammalian and insect cell cultures as well as transgenic animals have been established for commercial protein production. Each of these systems has specific benefits and short comings with respect to costs, scalability and safety. Plant-based transient expression platforms have become leading manufacturing technology due to the advantages in protein production yield and speed. Kopertekh and Schiemann [1] describe the recent advances in current design, status and future perspectives of plant transient expression systems for the production of biopharmaceutical proteins and provide the most illustrative examples of pharmaceutical proteins produced by transient expression in plants. The review article by Komarova et al. [2] focuses on the feasibility of plant-based systems for recombinant antibody production demonstrating illustrative examples of products and highlighting the beneficial properties of such platforms. To date, monoclonal antibodies are already broadly used in anti-cancer therapy but many have several disadvantages resulting in insufficient efficacy and side-effects. Kholodenko et al. [3] describe the potential applications of various types of antigen-binding fragments from antibodies as separate molecules or as a part of complex conjugates in anti-cancer therapy focusing on their structural features. Heat shock proteins (HSPs) represent multifunctional agents and are broadly involved in the activation of the immune response against tumors. These features are exploited in HSP-based vaccines aimed at inducing cytotoxic responses against tumor cells. Baldin et al. [4] reviewed the recent advantages in this field, but also focused on the problems of identifying and selecting the tumorspecific antigens suitable for HSP-based vaccine development. Potentially novel antigenic epitopes used in HSPbased vaccines may increase efficacy and allow for an extension of the range of target tumors. Large parts of known proteins possess enzymatic activity. So far, some of them are already being exploited in different enzymic therapy assays. The review article by Pokrovsky and coworkers [5] is focused on the family of amino acid degrading enzymes. Available therapeutic applications involving these enzymes are based on the deprivation of certain amino acids for the treatment of amino acid-dependent cancers, which exploit the compromised metabolism of malignant cells. The focus of the article is on L-asparagine, L-methionine, L-arginine and L-lysine degrading enzymes and their formulations as promising agents for the treatment of several types of cancers. Plants may serve not only as biofactories for pharmaceutical proteins but also as a source of novel enzymes possessing unique functions, and, in particular, as in the case of proteolytic enzyme production. Balakireva et al. [6] summarizes the recent advances and possible biomedical applications for plant proteases, proposing further development of plant-derived proteolytic enzymes from the biotechnology and pharmaceutical industries for the treatment of different diseases. Shekhter, Balakireva et al. [7] cover an area dedicated to collagenolytic enzymes. This review contains not only the data on existing collagenase-based medications and their applications in different collagen-related diseases and conditions, but collagenases from different sources for their potential application in enzymatic therapy are also proposed. Collagen has been successfully used in medicine for over 50 years. More recently collagen-based materials have been successfully applied as treatments for chronic wounds, burns, venous and diabetic ulcers, in plastic, reconstructive and general surgery, urology, proctology, gynecology, ophthalmology, otolaryngology, neurosurgery, dentistry, cardiovascular and bone and cartilage surgery, as well as in cosmetology. The review article by Shekhter, Fayzullin and coworkers [8] contains details on classic and modern applications of collagen in medicine such as in soluble collagen injections, solid constructs reconstructed from solution, and decellularized collagen matrices used in regenerative medicine applications. Zernii et al. [9] covers the area of the treatment of corneal epithelial defects using therapeutic proteins. Such treatments could be applied to protect the corneal surface, mimicking tear components, stimulation of corneal wound healing, regeneration of corneal innervation, and suppressing oxidative stress, inflammation and neovascularization. The article summarizes the existing data on protein-based drugs for the treatment of corneal epithelial defects that are currently under preclinical development or testing in clinical trials, or that have been approved for medical use. Peptide signaling is one of the main animal chemical communication systems involved in a multitude of physiological processes. Several examples of drugs influencing peptidergic signaling show the important role of peptides in the mechanisms of specific pathological conditions and in pharmacology. Fetissov et al. [10] describes the recent advances in the development of bacterial protein mimetics of peptide hormones as a new class of protein-based drugs. The authors pay special attention to the development of potential drug based on bacterial α-MSH homolog ClpB and conclude that the original approach leading to the identification of E. coli ClpB as α-MSH mimetic protein can be also applied for identifying mimetic proteins of other peptide hormones and developing a new type of peptide-like protein-based drugs. Human mucin MUC1 was discovered approximately 40 years ago as a component of milk fat globules, and to date it is assumed to play an important role in cell signaling as well as in all the stages of oncogenesis, from malignant cell transformation to tumor dissemination. Rubtsov et al. [11] describe the evolution in the understanding of MUC1 function, which has identified this molecule as a potential a potential target for anticancer therapy. One more potential protein target is described in detail in the review article by Orlov et al [12]. This article is dedicated to Na+,K+-ATPase as a molecular target for the treatment of tissue fibrosis, and takes into account recent data showing that cardiotonic steroids (CTS) that are known as potent inhibitors of Na+,K+-ATPase affect myofibroblast differentiation in a cell type-specific manner. In summary, the contributors to this special issue highlighted various topics within area of selection, development, production and application of biopharmaceutical proteins. We hope that this special issue will serve as a useful resource of the recent progress in these areas while offering inspiration to the broad spectrum of scientists involved.

The first monoclonal blicking TNF has been recently approved in 2013, and biosimilars represent a key opportunity for doctors caring for infla mmatory bowel disease. Multiple issues are still contreoversial and deserve full attention. Aim of the issue is to review the state of the art of biosimilars in inflammatory bowel disease.

Sub topics:

1. Introduction: Biosimilars, challenges and opportunities

2. Biosimilars and originators: similarities and differences

3. Biosimilars in IMID: efficacy and safety

4. Biosimilars in IBD: efficacy, safety and immunogenicity

5. The regulatory process of biosimilars

6. Patient's profile for biosimilars in IBD

7. Can we extrapolate data from one IMID to another one?

8. The problem of naming: which name for which biologic

9. Cost issues with biosimilars: what can be expected?

Development of robust, sensitive and reproducible methods for diagnosing a diseases is crucial for the effective therapy. A major challenge facing modern medicine is not only rapid and accurate diagnosing a disease in an early stage but also minimizing the invasiveness of the diagnostic technique. Currently, metabolomics is used for the discovery of diagnostic biomarkers of various diseases, to better understand their complexity and monitor the metabolic biomarkers during therapeutic intervention. Metabolic profiling is usually defined as a qualitative analysis and quantification of the metabolites which are associated with particular path. This approach may also give clues to personalized treatments for various diseases by providing useful information about the response to treatment. A prerequisite for the clinical use of biomarker is standardization of analytical methods used to metabolic profiling. In the last few years dozens of papers have been published on application of separation techniques coupled to mass spectrometry or nuclear magnetic resonance to identification biomarkers of several diseases. Although impressive improvements have been observed methodological challenges are still running. The scope of this Issue focuses on the strategies and current challenges in metabolomics in cancer; cardiology, steroid metabolomics and personalized medicine; direct biomarkers of alcohol consumption; applications of electronic noses in medical diagnostics; current progress of lipid analysis in metabolic diseases, as well as application of chromatography coupled to mass spectrometry to microorganisms detection. In the first review, by Burton and Ma [1] new achievements in urinary metabolomics, including application of hyphenated techniques in untargeted and targeted metabolomics applied to cancer biomarker discovery were described. The Authors pointed that urinary metabolomics has benefitted from recent technological developments in nuclear magnetic resonance, mass spectrometry, gas and liquid chromatography, and capillary electrophoresis; and discussed technical and clinical limitations in addition to the emerging challenges in the field of urinary metabolomics. Extensive metabolic profiling in urine has revealed a significant number of altered metabolic pathways and putative biomarkers, including pteridines, modified nucleosides, and acylcarnitines, that have been associated with cancer development and progression. The contribution by Kotłowska and Szefer [2] takes into consideration challenges and recent developments in steroidbased metabolomics and its potential in the area of clinical biomarkers discovery. The Authors have described the application of hyphenated techniques including GC-MS and LC-MS later combined with data processing using chemometric techniques. Moreover, application of steroid-based metabolomics in the studies on cancer, mental, and central nervous system disorders, adrenal diseases, endocrine disorders, of metabolism, impact of drug therapy, influence of dietary components, doping control, or prolonged physical activity was described. Apart from that, the main research targets in metabolomics are cardiovascular diseases due to their social and medical relevance, as well as the important role that metabolic changes play in their pathogenesis and evolution. Metabolomics can be used for a full spectrum of cardiovascular diseases: from risk assessment to myocardial infarction and heart failure. However, despite numerous studies describing the recent achievements in application of metabolomics in cardiovascular diseases, it has not yet been used in routine clinical practice. In the review by Barba et al. [3], application of metabolomics in the area of cardiovascular diseases was described. The usefulness of mass spectrometry in the qualitative and quantitative analysis of lipids was shown in Mika et al. [4] review. The Authors pointed that MS techniques combined with: GC, HPLC, and MALDI are the most commonly used in lipid analysis. Their application in lipidomics of obesity and other metabolic alterations, such as metabolic syndrome, diabetes, atherosclerosis, and nonalcoholic fatty liver disease are discussed in detail. The review by Spodzieja et al. [5] covers recent developments in discovery of biomarkers in different types of amyloidosis. The Authors described application of hyphenated techniques coupled with mass spectrometry in analysis of proteins occurring in tissues, blood and cerebrospinal fluid as a tools for diagnosis of amyloidosis, the current trends in improved pathogens separation and detection methods and their subsequent use in medical diagnosis. Whereas, the development of analytical and biological methods in the analysis of microorganisms, in biological and environmental samples such as blood, urine, lymph, and wastewater was presented in the publication by Chylewska et al. [6] In addition to describing the structure, surface, properties, size of microbes, and then pivotal points in the bacteria, viruses, and fungi, the Authors showed the progress, limitations, and challenges of separation techniques in selective fractionation of microorganisms. Application of hyphenated techniques for LMWH anticoagulants separation was described by Sadowski et al. [7]. These compounds mainly prevent blood clotting and growing of the existing clots in blood vessels. The Authors indicated that sensitive and high resolution analytical methods such as UHPLC play an increasingly important role in the analysis of LMWHs. Different types of liquid chromatography including SAX chromatography and RPIP chromatography and their use for di- and oligosaccharide components analysis of LMWHs were described. The HILIC chromatographic method and 2D LC method for separation and structural characterization of heparin anticoagulants were also described. The review by Woźniak et al. [8] covers recently published studies focusing on the sample preparation methods and chromatographic or biochemical techniques for the determination of alcohol biomarkers in whole blood, plasma, serum, and urine. Possibilities and limitations of separation techniques in routine analytical toxicology for monitoring alcohol consumption or sobriety during alcohol therapy were discussed. In the review by Wojnowski et al. [9], the use of electronic nose technology to identify aromas in a way parallel to the biological olfaction was described. Electronic noses are a non-invasive tool useful for early detection of human diseases based on exhaled air analysis, volatile fractions, blood, saliva, sweat, other body fluids and skin odor. Every pathological change affects the chemical composition of body fluids, and when registering these changes, it is possible to diagnose early disease. The development of this technology enables the identification of potential patients suffering from diabetes mellitus, asthma, uremia, tuberculosis or monitoring of dialysis progress and diagnosis of infections and cancer such as lung cancer and breast cancer. The comprehensive summary of research in medical diagnostics using electronic noses was presented in this review. Along this line, in the paper by Mpanga et al. [10], determination of urine metabolic fingerprints in urogenital tract cancer patients and healthy controls was done. GC-MS and LC-MS were applied to urine metabolic profiles identification. The Authors showed a panel of various statistically significant metabolites between urogenital cancer and healthy groups. Those compounds belong to different physicochemical groups such as carbohydrates, nucleosides, purines, and amino acids. It was also found that two metabolites, namely glucocaffeic acid and lactic acid, can be considered as markers in bladder, prostate, and kidney cancer. The Authors pointed to future directions which can lead to its use in clinical settings. In turn, the main goal of the study by Wawrzyniak et al. [11] was to determine plasma metabolomic profiles in resistant and non-resistant hypertensive patients. Application of LC-ESITOF/ MS allows to verify patients compliance to antihypertensive pharmacotherapy what was a crucial step before biochemical interpretation 19 up-regulated and 13 down-regulated metabolites in RH were identified. The Authors pointed that abnormal metabolomic profiles are linked mainly to lipid, amino acids, and purine metabolism. Lipids play many important roles in disease processes and lipidomics is a specialized subset of metabolomics.