Functionalized chitosan as a promising platform for cancer immunotherapy: A review

Immunotherapy is an emerging treatment option for use following traditional cancer treatments (surgical resection, radiotherapy and chemotherapy). Due to the complexity of the tumor environment, a single immunotherapy drug cannot readily reach the target site and frequently causes adverse reactions. Chitosan has been used in this emerging field because of its biodegradable, biocompatible, nonimmunogenic and nontoxic properties. Chitosan has been used as a carrier of immunotherapeutic agents to improve bioavailability, regulate the immune system and enhance antitumor response. The easily modified structure of chitosan allows for the construction of many different delivery vectors for better application in immunotherapy. Here, we review the recent applications of chitosan and its derivatives as delivery vectors in cancer immunotherapy, as well as discuss limitations and clarify current trends and future directions. In conclusion, chitosan has a promising future as a delivery material in immunotherapy.