Thermosensitive Biomaterials in Tissue Engineering
We have described the different thermosensitive biomaterials including synthesis, properties and phase transition mechanisms, and we have also attempted to define the corresponding applications of the hydrogels in tissue engineering. The thermosensitive hydrogels are constituted chitosan and its derivatives, poly PNIPAAM-based copolymers, PEO/PPO copolymers and its derivatives, PEG/PLGA block copolymers, PEG/PLA block copolymers, PEG/PCL block copolymers and others. In addition, we provided a brief introduction of dual-responsive biodegradable hydrogels. These hydrogels exhibited sol–gel transition behavior—a liquid state at low temperature, forming a gel when the temperature increased to the physiological temperature, 37 °C. They have been widely used in tissue regeneration containing bone, cardiac tissue, cartilage and so on. The structures of the hydrogels were similar to extracellular matrix (ECM); meanwhile drugs, active factors, genes and cells could all be incorporated into the hydrogels to promote regeneration. In summary, there is considerable potential in using thermosensitive hydrogels in tissue engineering.