Preface
Page: ii-iii (2)
Author: Tilak Saha, Manab Deb Adhikari and Bipransh Kumar Tiwary
DOI: 10.2174/9789815123975123010002
Probiotics as Potential Remedy for Restoration of Gut Microbiome and Mitigation of Polycystic Ovarian Syndrome
Page: 1-33 (33)
Author: Rejuan Islam and Tilak Saha*
DOI: 10.2174/9789815123975123010004
PDF Price: $15
Abstract
Polycystic ovarian syndrome (PCOS) is the most frequent endocrine
disorder currently plaguing women. There are many factors associated with high
androgenicity in the female body. Dysbiosis of gut microbiota may be one of the
primary reasons that initiate PCOS. Emerging evidence suggests that some plastics,
pesticides, synthetic fertilizers, electronic waste, food additives, and artificial hormones
that release endocrine-disrupting chemicals (EDCs) cause microbial Dysbiosis. It is
reported that the permeability of the gut is increased due to an increase of some Gram-negative bacteria. It helps to promote the lipopolysaccharides (LPS) from the gut lumen
to enter the systemic circulation resulting in inflammation. Due to inflammation,
insulin receptors' impaired activity may result in insulin resistance (IR), which could be
a possible pathogenic factor in PCOS development. Good bacteria produce short-chain
fatty acids (SCFAs), and these SCFAs have been reported to increase the development
of Mucin-2 (MUC-2) mucin in colonic mucosal cells and prevent the passage of
bacteria. Probiotic supplementation for PCOS patients enhances many biochemical
pathways with beneficial effects on changing the colonic bacterial balance. This way of
applying probiotics in the modulation of the gut microbiome could be a potential
therapy for PCOS.
Antibody Therapy as Alternative to Antibiotics
Page: 34-53 (20)
Author: Manoj Lama*
DOI: 10.2174/9789815123975123010005
PDF Price: $15
Abstract
In the 1890s, Behring and Kitasato established the principle of serum
therapy, which proved useful in treating infectious diseases. However, by the 1940s,
serum therapy was abandoned mainly due to complications associated with the toxicity
of heterologous sera and the introduction of more effective antibiotics. Although the
availability of antibiotics had a tremendous impact on saving lives from infectious
diseases, there was a rapid emergence of antibiotic resistance. As a result, an
alternative therapy is being given due consideration. With the advent of antibody
production technology, antibody therapy has gained interest as a promising treatment
for emerging infectious diseases. Some monoclonal antibodies (mAbs) had already
been approved for the treatment of certain infectious diseases. Many mAb candidates
are currently in different phases of clinical testing for a variety of infectious pathogens.
There is hope that antibody therapy may appear as a promising treatment option against
infectious diseases in the near future.
Cationic Amphiphiles as Antimicrobial Agents
Page: 54-75 (22)
Author: Sovik Dey Sarkar and Chirantan Kar*
DOI: 10.2174/9789815123975123010006
PDF Price: $15
Abstract
Numerous antimicrobial peptides (AMP) obtained from natural sources are
currently tested in clinical or preclinical settings for treating infections triggered by
antimicrobial-resistant bacteria. Several experiments with cyclic, linear and
diastereomeric AMPs have proved that the geometry, along with the chemical
properties of an AMP, is important for the microbiological activities of these
compounds. It is understood that the combination of the hydrophobic and hydrophilic
nature of AMPs is crucial for the adsorption and destruction of the bacterial membrane.
However, the application of AMPs in therapeutics is still limited due to their poor
pharmacokinetics, low bacteriological efficacy and overall high manufacturing costs.
To overcome these problems, a variety of newly synthesized cationic amphiphiles have
recently appeared, which imitate not only the amphiphilic nature but also the potent
antibacterial activities of the AMPs with better pharmacokinetic properties and lesser in
vitro toxicity. Thus, amphiphiles of this new genre have enough potential to deliver
several antibacterial molecules in years to come.
Amphiphilic Nanocarriers to Fight Against Pathogenic Bacteria
Page: 76-100 (25)
Author: Amit Sarder* and Chanchal Mandal
DOI: 10.2174/9789815123975123010007
PDF Price: $15
Abstract
The emergence and expansion of antibiotic resistance in pathogenic bacteria
have become a global threat to both humans and animals. Immense use, overuse and
misuse of antibiotics over several decades have increased the frequencies of resistance
in pathogenic bacteria and resulted in significant medical problems. To fight against the
widespread drug-resistant pathogenic bacteria has become a terrific challenge for the
modern healthcare system. The major challenges to fight against pathogenic bacteria
involve long-term antibiotic therapy with combinations of drugs. The abundance of
resistance mechanisms in pathogenic bacteria has compelled many therapeutic
antibiotics to become ineffective. As a result, the elimination of drug-resistant
pathogenic bacteria requires a judicious strategy. The advent of nanotechnology has
unveiled a new horizon in the field of nanomedicine. Nanoparticle-based techniques
have the potential to overcome the challenges faced by traditional antimicrobials. In
this way, self-assembling amphiphilic molecules have emerged as a fascinating
technique to fight against pathogenic bacteria because of their ability to function as
nanocarriers of bactericidal agents and interact and disrupt bacterial membranes.
Nanocarrier-based drug delivery systems can mitigate toxicity issues and the adverse
effects of high antibiotic doses. The focus of this chapter is to discuss various
amphiphilic nanocarriers and their roles and possibilities in fighting against pathogenic
bacteria.
Biological Importance of Some Functionalized Schiff Base-Metal Complexes
Page: 101-123 (23)
Author: Mintu Thakur and Kinkar Biswas*
DOI: 10.2174/9789815123975123010008
PDF Price: $15
Abstract
Schiff base ligands or compounds are useful in modern inorganic chemistry.
Numerous transition metal-based catalysts have been synthesized with Schiff base
scaffolds. The application of such Schiff bases is also found in biological studies.
Herein, we have discussed the various synthetic procedures of diversified Schiff base
compounds and their metal complexes. The biological activity of those complexes has
also been delineated in this chapter with special emphasis. Various metal complexes
[Co(II), Ni(II), Cu(II), Zn(II) and Fe(III)] with different Schiff base compounds
displayed anti-fungal activity. Similarly, anti-viral activity was seen with Co(II) and
Pd(II) metal complexes. Many Schiff base-metal complexes are found, which showed
anti-cancer activity against various carcinoma cells like HpG2, MCF-7, A549,
HCT116, Caco-2 and PC-3. Similarly, the transition metal complexes (generally 1st and
2
nd row) of Schiff bases also exhibited good anti-bacterial activity against various
bacterial strains. The ionic-liquid-tagged Schiff bases have also been found to be good
anti-microbial agents
Metal-Organic Frameworks (MOFs) for the Antimicrobial Applications
Page: 124-141 (18)
Author: Nazeer Abdul Azeez, Sapna Pahil, Surendra H. Mahadevegowda and Sudarshana Deepa Vijaykumar*
DOI: 10.2174/9789815123975123010009
PDF Price: $15
Abstract
Metal-Organic Frameworks (MOFs) are a class of porous crystalline
materials made-up of transition-metal cations linked with multidentate organic ligands
by the coordination bonds. The strong, flexible frameworks and the porous structure of
the MOFs establish them as an effective carriers of various functional compounds, such
as gases, drugs, and anti-microbial agents. The MOFs render high loading capacity and
sustained release, which is the desired property in anti-microbial applications. Similar
porous material for the anti-microbial application is Zeolite, however, it is more
complex to synthesize than MOFs. Currently, MOFs are used mainly in catalysis, gas
separation and storage, and water purification applications. In the applications as anti-microbial agents, MOFs are just emerging into the field application from the laboratory
scale. Hence, this chapter discusses the properties, synthetic procedures, anti-bacterial
mechanisms and various forms of MOFs for anti-microbial applications. The MOFs are
often doped with metal nanoparticles, polymers, and metal-polymer complexes. Each
category of MOFs has a different mechanistic approach to inhibiting microbial colony
growth. In this regard, this chapter will provide sufficient information on the MOFs,
which will help to understand their significance in anti-microbial applications and their
scope
Biogenic Metal Nanoparticles: A Sustainable Alternative to Combat Drug-Resistant Pathogens
Page: 142-171 (30)
Author: Palas Samanta, Sukhendu Dey, Sushobhon Sen and Manab Deb Adhikari*
DOI: 10.2174/9789815123975123010010
PDF Price: $15
Abstract
The natural environment acts as the largest ‘bio-laboratory” of yeast, algae,
fungi, plants etc., which are used as an abundant source of biomolecules. These
different biomolecules play vital roles in the formation of different biogenic metals or
metalloid nanoparticles. Recently, the overburden from the different microbial diseases
has increased rapidly in different application sectors, viz., drug delivery, DNA analysis,
cancer treatment, antimicrobial agents, water treatment and biosensor and catalysts, as
a result of multipurpose work occurrence globally. The indiscriminate and arbitrary use
of antibiotics in clinical practice has spurred the emergence of potentially lifethreatening multidrug-resistant pathogens. In the quest for novel antimicrobial agents,
the current interest is to develop potent antimicrobial agents which exhibit broadspectrum bactericidal activity and possess a mechanism of action that does not readily
favor the development of resistance. The use of nanoscale materials as bactericidal
agents represents a novel paradigm in antibacterial therapeutics. Actually, eco-friendly,
sustainable modern approaches, such as green syntheses of different biogenic metals or
metalloid nanoparticles, are cost-effective and environment-friendly, and they are used
as strong antimicrobial agents. This chapter focuses on synthesizing biogenic metal or
metalloid nanoparticles with special emphasis on microbial synthesis, particularly from
yeast, bacteria, algae, fungi, plants extract, etc. Finally, a detailed description of the
biosynthesis mechanism using different green sources, along with their antimicrobial
activity and mode of action, has been presented.
2D Molybdenum Disulfide (MoS2 ) Nanosheets: An Emerging Antibacterial Agent
Page: 172-189 (18)
Author: Praveen Kumar and Amit Jaiswal*
DOI: 10.2174/9789815123975123010011
PDF Price: $15
Abstract
The development of resistance against antibiotics in microorganisms has led
to the search for alternatives that can effectively kill microbes and will have a lesser
probability of the generation of resistance. In this regard, nanomaterials have emerged
as protagonists demonstrating efficient antibacterial activities against drug-resistant
strains. Amongst nanomaterials, 2D nanosheets have attracted attention as an
antibacterial agent due to their sheet-like features, having sharp edges and corners
which can pierce through bacterial membranes, subsequently leading to membrane
damage. The present chapter discusses the antibacterial potential of one such 2D
material, transition metal dichalcogenides, specifically MoS2
nanosheets and their
composites. A brief discussion about the synthesis of MoS2
nanosheets is presented,
and a detailed overview of its application as an antibacterial agent is illustrated. The
mechanism of action of antibacterial activity of 2D MoS2
nanosheets is discussed,
which shows that these nanosheets can cause bacterial cell death through membrane
damage and depolarization, metabolic inactivation and generation of reactive oxygen
species (ROS). Further, the photothermal property and the intrinsic peroxidase-like
activity in certain conditions can also show antibacterial activity, which is summarized
in the chapter along with the biocompatibility evaluation.
Metallic and Non-Metallic Quantum Dots as Potent Antibacterial Agents
Page: 190-214 (25)
Author: Areeba Khayal, Kabirun Ahmed, Amaresh Kumar Sahoo* and Md Palashuddin Sk*
DOI: 10.2174/9789815123975123010012
PDF Price: $15
Abstract
The emergence of antibiotic-resistant bacteria poses a critical public health
issue worldwide, which demands the development of novel therapeutic agents as viable
alternatives to antibiotics. The advent of nanoscience and technology offers the
synthesis of several potential anti-microbial agents that are effective against both
Gram-positive and Gram-negative bacterial strains. One such nanoscale material that
fascinated researchers due to its unique optoelectronic properties is Quantum Dots
(QDs). Moreover, these are found to be highly bactericidal, even against resistant
bacterial infections. Thus, a significant number of researches have been going on
globally to employ QDs as potent bactericidal agents alone or in combination with
antibiotics. Studies demonstrated that intracellular uptakes of QDs elevate the level of
reactive oxygen species (ROS) inside the cells, which turns-on cascades of intracellular
events that cause damage to DNA and proteins. However, the inherent reactive nature
of these metallic and semiconductor QDs raises huge concern for translational research
as these are found to be cytotoxic and non-biocompatible. Moreover, the human body
does not have a proper sequester mechanism to remove these metallic ions from the
body, which limits its direct applications. Recent progress in this line of interest has
focused on developing non-metallic quantum dots, such as carbon dots (CQDs) and
Black Phosphorus quantum dots (BP QDs) which showed less toxicity and
immunogenicity suitable for real-life applications. Therefore, in the present chapter, we
are going to discuss the recent development of bactericidal QDs and various types of
surface functionalization illustrated recently to increase biocompatibility.
Photodynamic Therapy: A Viable Alternative Strategy to Control Microbial Invasions
Page: 215-248 (34)
Author: Moushree Pal Roy*
DOI: 10.2174/9789815123975123010013
PDF Price: $15
Abstract
Antimicrobial photodynamic therapy (aPDT) is a new-age therapeutic
technique that by principle, focuses on the eradication of target cells by highly
cytotoxic reactive oxygen species (ROS) generated through the activation of a chemical
photosensitizer (PS) molecule with visible light of appropriate wavelength. The
cytotoxic species can arise via two main mechanisms known as Type I and Type II
photoreactions: the former leads to the generation of ROS and the latter to the
formation of the singlet oxygen. These highly reactive oxidants can bring about
instantaneous oxidation of a great array of biological molecules, causing havoc to the
target cell. This technique provides significant advantages over conventional
antimicrobial therapies in practice which are now facing the burning threat of growing
complete resistance against them. To combat this world-wide health concern, new
treatment strategies are the need of the time while ensuring no further rise of resistance
against those alternative therapies, and aPDT appears to be highly promising in this
aspect by fulfilling all the demands at the same time. It appears not only equally
effective at killing both antibiotic-sensitive and multi-resistant bacterial strains, but also
highly selective, non-invasive and rapid in action than other antimicrobial agents, and
there have been no reports of resistance till date. The success of this phototherapy relies
on several factors, including the target cell type, reaction conditions, and the type,
molecular structure and cytolocalization of the PS; because its potency depends on the
distribution, high reactivity and short lifetime of ROS as well as the PS itself in
electronically excited states.
Subject Index
Page: 249-253 (5)
Author: Tilak Saha, Manab Deb Adhikari and Bipransh Kumar Tiwary
DOI: 10.2174/9789815123975123010014
Introduction
Recent Trends and the Future of Antimicrobial Agents provides a significantly expanded overview of the topic with updated research in a broader context on the development of alternative approaches against microbial infections. This part primarily describes the use of probiotics, chemically synthesized compounds and nanomaterials as antimicrobial agents. The first chapter describes the potential of probiotics for the restoration of gut microbiomes. Amongst various antimicrobial agents, the use of antibodies has recently been investigated as a potential remedy. A chapter on antibody-based therapy as an alternative to antibiotics has been included. Chemical synthesis has eased the development of target-based prospective drug molecules against microorganisms. Chemically synthesized cationic amphiphiles and amphiphilic nanocarriers as antimicrobial agents have been discussed with sufficient detail in two different chapters. Research and progress in Schiff Base-Metal Complexes and Metal-Organic Frameworks for their antimicrobial applications have also been described in two separate chapters. Independent chapters discussing the design, synthesis and antimicrobial applications of biogenic metal or metalloid nanoparticles, bactericidal QDs and MoS2-based antibacterial nanocomposites have fulfilled the aim of incorporating cutting-edge research in the areas of alternative antimicrobials. Also, a new-age approach to combat microbes, antimicrobial photodynamic therapy (aPDT), is discussed in the final chapter of the edited volume. This part intends to provide the readers with an updated and broad view of research and development in alternative remedial approaches against microbial infections. The contents cater to the information needs of professionals and learners in academia, industry and health services who aim to learn the most significant experimental and practical approaches towards finding alternatives to existing antimicrobial therapies.