Thermosensitive Hydrogels and Advances in Their Application in Disease Therapy

Thermosensitive hydrogels, having unique sol-gel transition properties, have recently received special research attention. These hydrogels exhibit a phase transition near body temperature. This feature is the key to their applications in human medicine. In addition, hydrogels can quickly gel at the application site with simple temperature stimulation and without additional organic solvents, cross-linking agents, or external equipment, and the loaded drugs can be retained locally to improve the local drug concentration and avoid unexpected toxicity or side effects caused by systemic administration. All of these features have led to thermosensitive hydrogels being some of the most promising and practical drug delivery systems. In this paper, we review thermosensitive hydrogel materials with biomedical application potential, including natural and synthetic materials. We describe their structural characteristics and gelation mechanism and briefly summarize the mechanism of drug release from thermosensitive hydrogels. Our focus in this review was to summarize the application of thermosensitive hydrogels in disease treatment, including the postoperative recurrence of tumors, the delivery of vaccines, the prevention of postoperative adhesions, the treatment of nervous system diseases via nasal brain targeting, wound healing, and osteoarthritis treatment.