Synthesis, physicochemical and biological studies of macromolecular carriers of antimicrobial peptides

One of the main problems of modern medicine is the growing phenomenon of microbial resistance as a result of uncontrolled use of antibiotics. Every year in the European Union countries die from injections caused by antibiotic-resistant bacteria, approximately 25,000 people. The aim of the project is to research the synthesis, physicochemical and biological properties of macromolecular carriers of antimicrobial peptides. The influence of the topology of polymer matrices, the content and distribution of AMPs associated with the matrix on the efficiency of polymer-peptide systems will be determined. In addition, the kinetics of the release of more active substances from polymer matrices and the effectiveness of the new systems in microbiological tests will be determined. Polymer matrices will be obtained by ring-opening polymerization of cyclic monomers (ROP) against selected biocalallors (lipases). Ring opening bypasses the step of generating leave groups, which may limit the propagation rate and the molecular weight of the product. The use of enzymes in the polymerization process will avoid toxic residues of classic organometallic catalysts. The synthesis of polymer matrices will be carried out in organic solvents. As shown by the results of experimental studies, this allows for higher enantioselectivity and thermostability of lipases than in the aquatic environment. Ionic liquids (ILs) will be selected as the reaction medium due to their low vapor pressure and high thermal and chemical stability. In the medium of ionic liquids (with a specific structure), lipases show higher activity and selectivity than traditional organic solvents. After the end of the process, the reaction products can be easily separated, e.g. by extraction. The synthesis of carriers will be carried out in a classic and microwave reactor. The use of microwave radiation has many advantages: it is an environmentally friendly process, as it allows to significantly accelerate the duration of the reaction, while maintaining control over its course. Peptides will be attached to the prepared polymer matrices, e.g. by esterification of functional groups of peptides and obtained polymers and by polyaddition with aliphatic and cycloaliphatic diisocyanates. The project will use commercially available peptides and new, synthetic peptide analogs, incl. eitropin 1.l. protegrin 1, teporin A. amiganan MDI 226, pexiganan MSI 78 synthesized in cooperation (as in previous studies) with the Medical University of Gdańsk. Peptides will be synthesized by the Fmoc method in a microwave reactor on a polystyrene support (polystyrene resin modified with a Rink-amide linker). The structure of the obtained, large-molecule antimicrobial peptide conjugates will be determined by a number of instrumental methods: 1H and 13C, CP / MAS, UV-Vis, ET1R, GPC, SEM and thermal properties by DSC-TG. Depending on the structure of the conjugate and the content of the active substance, the ability and speed of hydrolytic degradation in buffer solutions and biodegradation in the presence of hydrolases will be determined. The effectiveness of the produced, new carrier-AMP systems will be tested in microbiological tests. Biocompatibility, cytotoxicity and genotoxicity will be verified in vitro by means of rapid diagnostic tests. The project will verify the effectiveness and the possibility of using the produced matrices as carriers of antimicrobial peptides. The relationship between the structure of the obtained biomaterials and the kinetics of active substance release will be demonstrated. In the longer term, the results of the project may contribute to the development of application research in the fight against drug resistance of microorganisms. The project is interdisciplinary and the results obtained after its completion may significantly contribute to the development of medical chemistry, pharmaceutical chemistry, biomaterials chemistry and pharmacy.