Infection Resistant Surface Coatings by Polymer Brushes: Strategies to Construct and Applications

Bacteria-assisted infections on biomaterials used inside a body as an implant/device are one of the major threats to human health. Microbial-resistant coatings on biomaterials can potentially be considered to mitigate the biomaterial-associated infections. Usually biomaterials with leachable antimicrobial coatings, though economically attractive, provide only short-term protection of the surface against bacteria. Therefore, a stable, nonfouling or bactericidal, and biocompatible polymeric coating is highly desirable. In this regard, polymer brushes, defined as polymer chains tethered to a surface by one end, with suitable anti-infective functionality, represent a useful class of stable coatings which are covalently connected to the underlying surface, thus prolonging the infection resistance of the coated surface. Surface-initiated atom transfer radical polymerization (SI-ATRP) is a versatile technique for the generation of polymeric brushes via "grafting from" way. In this review, we have attempted to give a brief overview about the recent developments of surface coatings by infection-resistant polymer brushes synthesized via SI-ATRP and their applications in the biomedical field. On the basis of their charges, these anti-infective brushes can be classified into five different categories such as neutral, cationic, anionic, zwitterionic, and mixed brushes. The working mechanism of each type of brush in repelling (nonfouling/bacteriostatic) and/or killing (bactericidal) the bacteria has also been discussed. A brief summary of their future scope is also highlighted.