Synthesis, characterizations, and release mechanisms of carboxymethyl chitosan-graphene oxide-gelatin composite hydrogel for controlled delivery of drug

Hydrogels have received immense interest for various biomedical applications owing to their hydrated environment and outstanding properties. However, challenges still exist regarding utilizing hydrogels in the application of drug delivery and release, because of the lack of controllability, actuation and quick-response properties. Here, the functionalized carboxymethyl chitosan-graphene oxide-gelatin composite hydrogel with excellent swelling property, high biocompatibility and drug delivery efficiency was prepared by ionic crosslinking. Our study found that the carboxymethyl chitosan-graphene oxide-gelatin composite hydrogel exhibited porous structures and the pores distribute randomly but arrange regularly in the cross section. In addition, the thermal stability and excellent swelling ratio of the carboxymethyl chitosan-graphene oxide-gelatin composite hydrogel were improved. As a consequence, the CMCS-GO-Gelatin-3 exhibited the maximum cumulative release rate and the cumulative release amount of this composite hydrogel was 74.6 under the condition of buffer solution pH = 6.5 PBS and 89.1 under the condition of buffer solution pH = 7.4 PBS. Therefore, this composite hydrogel showed improved drug delivery efficiency and achieved drug prolonged administration to 24 h. This work highlights that carboxymethyl chitosan-graphene oxide-gelatin composite hydrogel will be a promising candidate for the applications in biomedical engineering.