Surface functionalization of biomaterials by radical polymerization

One effective strategy in the field of biomaterials is to develop biomimetic interfaces to modulate the cell behavior and promote tissue regeneration and surface modification is the best way to obtain biomaterial surfaces with the desired biological functions and properties. Surface radical polymerization offers many advantages compared to other methods, for instance, low cost and simplicity, ability to control the surface chemistry without changing the properties of the bulk materials by introducing high-density graft chains and precisely controlling the location of the chains grafted to the surface, as well as long-term chemical stability of the chains introduced by this method due to the covalent bonding. Because of the precise control of the macromolecules and easy preparation, controlled/living radical polymerization has been widely used to modify biomaterials. There are three main techniques: atom transfer radical polymerization (ATRP), nitroxide-mediated polymerization (NMP), and reversible radical addition-fragmentation chain transfer (RAFT) polymerization. Some other grafting methods such as plasma-induced polymerization, irradiation-induced polymerization, and photo-induced polymerization also have great potential pertaining to functionalization of biomaterials and tailoring of surface chemistry. This paper summarizes recent advances in the various grafting polymerization methods to enhance the surface properties and biological functions of biomaterials.