Improving tumor chemotherapy effect using an injectable self-healing hydrogel as drug carrier

Chemotherapy has contributed greatly in clinical anti-tumor treatment. However, the traditional method of drug delivery by intravenous injection has several drawbacks, such as low delivery efficiency, high toxicity and frequent pain caused by injection. To overcome these defects, intra-tumor injection has been proposed in recent years, and the development of suitable carriers to locate the drug at the desired position for optimum dispersal is crucial to realize the superiority of intra-tumor injection. Herein, we report the application of a chitosan-based self-healing hydrogel, constructed through Schiff's bases, as an injectable drug carrier for in vivo intra-tumor therapy. This smart carrier could deliver highly concentrated anti-tumor drug (Taxol) to the desired position (human hepatocarcinoma tumor) for steady in situ release at a safe level. The self-healing drug carrier could adapt to the intra-tumor structure and regenerate as a whole, thus avoiding the fast leak of loaded drug, leading to admirable therapeutic effects compared with controls (direct injection of drug solution or use of non-self-healable thermal-sensitive hydrogel as the drug carrier). Due to its excellent biocompatibility and high operability, this injectable self-healing hydrogel might be a promising drug carrier for tumor chemotherapy and other medical applications.