Background: Immune system related pathologies affect an increasing number of patients every year, having potentially lethal consequences and requiring expensive and difficult tolerated treatments. This area of pathologies offers an excellent potential for the development of innovative solutions such as nanoformulations; this review aims to describe the main categories of nanostructured drug delivery platforms that have been developed in order to achieve a more effective, low toxic treatment in autoimmune pathologies.
Methods: We conducted a systematic search of peer-reviewed original studies focusing on nanoformulations suitable for use against autoimmune disorders. Each study was evaluated by at least two reviewers who applied inclusion and exclusion criteria in order to establish the quality of the research reported in the selected papers. The systematic screening of the literature also identified the most recent patents issued in the field of inflammatory/autoimmune diseases which were included in the current paper.
Results: One hundred ninety-seven bibliographic titles were included in the review of which fifty-three recently published patents. Twenty-one papers were selected to define the interaction between nanoformulations and the immune system triggering either immunosuppression or immunostimulation. Thirty-seven papers outlined the characteristics of liposomal formulations that have been reported as treatment for several autoimmune diseases including multiple sclerosis. Twentythree articles provided data on the main lipid nanoparticles of the first and second generation which may include physiological lipids with low cytotoxicity. Gold nanoparticles were described by thirteen papers which highlighted the advantages of the new hybrid organic-inorganic nanoparticles vs. the classical ionic gold compounds. Polymeric nanoformulations were the subject of fifty-nine papers that described their preparation as well as various advantages in the treatment of inflammatory disorders; dendrimers and polymeric micelles were included in the study. Thirty-three studies were selected to outline the benefits provided by the use of cyclodextrins as carriers for active drugs. The review also identified the possibility of producing combined nanoformulations (e.g. polymer/cyclodextrin, liposome/polymer) thus achieving superior therapeutic results.
Conclusion: Nanoformulations offer multiple advantages over the classical pharmaceutical formulations, the main ones being the precise targeted therapy with small doses of active drugs, longer circulating time in the bloodstream, and high loading capacity for diagnostic and therapeutic molecules; moreover, the nanoparticles may be functionalized in order to act as nanotheranostics within the larger frame of personalized medicine.