Polymer brush-based approaches for the development of infection-resistant surfaces

In this highlight, we discuss the current strategies for developing infection-resistant biomaterials by making them non-fouling, bactericidal or both. We focus on approaches that have used polymer brush systems by providing examples of hydrophilic non-fouling polymer brushes, those that incorporated bactericidal agents (antibiotics, antimicrobial peptides and proteins) and synthetic polyelectrolyte polymer brushes. We discuss the most important research reported in recent years and deliberate their merits, future potential and further developments required. Initially we give a brief account on the use of anti-adhesive hydrophilic polymer brushes as bacteria-resistant surfaces and their potential utility in short term applications. The importance of the chemistry and physical properties of the brushes is highlighted along with the need for the development of bactericidal coatings. Further, recent developments involving bactericide-releasing and contact killing coatings are discussed. Approaches based on antimicrobial peptide conjugated polymer brushes, those incorporating enzymes (e.g. lysozyme), viruses and chemical functionalities (polyelectrolytes) that can kill bacteria are highlighted. As an important criterion for the in vivo application of infection-resistant coatings, the biocompatibility of the modified surfaces is briefly discussed in each section. The covalent attachment, availability of multitude of functionalities for further modification, ability to alter the physical structure of the coating, biocompatibility, potential application to various biomedical surfaces and the robust mechanical properties of polymer brush systems make them ideal for further development as a novel surface coating to address biomaterial-associated infections.