Poly(N-isopropylacrylamide) based thermoresponsive polymer brushes for bioseparation, cellular tissue fabrication, and nano actuators

Many thermoresponsive surfaces for biomedical applications have been developed using various techniques for modifying substrates with thermoresponsive polymers. In addition, surface-initiated living radical polymerization methods such as atom-transfer radical polymerization (ATRP) and reversible addition–fragmentation chain-transfer (RAFT) polymerization have been developed as nano structure controlled surface modification methods for modifying thermoresponsive polymers to substrates. These polymerization techniques allow the accurate control of polymerization and the formation of densely packed polymer brush structures. The present review article summarizes a variety of thermoresponsive polymer brushes, mainly comprising poly(N-isopropylacrylamide) (PIPAAm), prepared by surface-initiated ATRP and RAFT polymerization. Self-oscillating polymer brushes as new nano-actuators are also discussed.