Chapter 4. Biomimetic Antimicrobial Polymers

Increased levels of antibiotic drug resistance of virulent bacteria is an urgent healthcare issue that needs to be rethought, not in terms of producing more potent antibiotics, but requiring a paradigm shift. A class of small proteins called host defense peptides are a promising area to understand the evolution of such peptides as an integral part of innate immunity system, and learn design principles which can be used to develop biomimetic synthetic polymers with antimicrobial properties. The goal of such research is to understand at a fundamental level the role of oft-repeated specific motifs present in such peptides, including presence of both charged and hydrophobic entities and facial amphiphilicity in their antimicrobial mechanism, and adopt them into the synthetic polymers. Another goal of such research is to use these peptides or biomimetic polymers as a platform to investigate a fundamental paradigm of biology: structure–function relationship. Recent studies show that many biomimetic polymers and a class of proteins called intrinsically disordered proteins are capable of acquiring functional structures under specific conditions without such a structure built into the system. Such capabilities open up the possibilities of design of smart polymers, which may be very cost-effective and functionally relevant when required. In this chapter we primarily focus on mechanistic design and computational details of biomimetic antimicrobial polymers and their interaction with model membranes, particularly highlighting the effect of such polymers on structural integrity of membranes.