Thermo-sensitive polymers in medicine: A review

A wide variety of smart polymer systems such as thermosensitive polymers (TSPs) have been developed and applied mimicking nature. TSPs are a class of macromolecules that exhibit bio-inspired behavior and have various applications such as drug delivery, tissue engineering, theranostic particles and bioseparation. An inherent feature of a living system is its ability to react in response to an external stimulus. The temperature dependence of polymer properties is the reason behind dramatic changes in morphology, solubility, shape and sol-gel transition. TSPs can be synthesized as hydrogel, micro- and nanoparticles, film, micelle and mussel-inspired materials. The architecture of TSPs determines their biomimetic patterns and allows one to expand their uses. TSPs can be used as systems for the controlled release of drugs to a specific organ, as well as scaffolds in tissue engineering. Multi-responsive and thermosensitive features of TSPs give rise to design of smart systems for special applications. For example, pH- and photo-responsive abilities in combination with temperature sensitivity can play a vital role in drug delivery and tissue engineering. In-depth knowledge about the structure-property relationship is a key factor to design a smart biomimetic polymer. In this review paper, the functional design of the TSPs, their biomedical applications and the road ahead for their developments are comprehensively overviewed.