Synthesis Of Injectable Photosensitive Chitosan-based Hydrogels And Their Application In Phototherapy

Cancer is one of the most serious diseases that can significantly damage a person’s health.Currently,there are a variety of therapeutic methods for cancer,cancer phototherapy has emerged as a promising treatment option due to its minimally invasive nature and significant therapeutic effect on tumors.Photothermal therapy(PTT)and photodynamic therapy(PDT)are two of the most common forms of phototherapy and have garnered extensive research interest in improving treatment outcomes due to their synergistic effect.Recently,researchers have developed numerous phototheranostic agents that utilize aggregation-induced emission luminogens(AIEgens)for use in PDT and PTT research,providing novel insights into developing safer and more effective cancer treatments.AIEgens are mostly coated with biocompatible materials and delivered to the tumor site by intravenous injection.Injectable hydrogels have high water content,flexibility and biocompatibility,and that mimic physiological tissue environments have been prevalently applied in the area of biomedical sciences.Compared to systemic treatment methods such as intravenous administration,local injection not only allows for controlled drug release but also reduces the systemic toxicity of the drug to normal tissues.In this project,we synthesized an AIEgens DBRA and crosslinked it with chitosan and glutaraldehyde to prepare a photosensitive hydrogel CDG hydrogel,which not only has suitable photothermal conversion efficiency and injectable,but also has effective reactive oxygen generation and biocompatibility.CDG hydrogel can be injected in situ into the peritumoral area and can exert its PTT and PDT effects.In vivo studies have shown that CDG hydrogel can significantly inhibit tumor growth and reduce tumor volume through the synergistic effect of PTT and PDT.This study provides a new and effective strategy for the preparation of injectable hydrogels by AIEgens and chitosan,and also presents an innovative approach to developing a versatile medical phototherapy platform with multiple functionalities.