Controlled Release Self-healing Hydrogel Based On Multicomponent Reaction

Self healing hydrogel is a kind of intelligent hydrogel which can be repaired by itself in a certain period of time after being subjected to external trauma.Most of the self-healing hydrogels have excellent biocompatibility because of their high similarity with biological tissues.However,due to the need to introduce self-healing functional group to hydrogel,self-healing hydrogels often require complex preparation processes.At the same time,pH,temperature,pressure and physiological toxicity also restrict the applications of self healing hydrogels in biomedical materials.In recent years,the researchers focused their attention on developing a self-healing hydrogel with simple synthesis process,mild self-healing condition,low cytotoxicity and other special properties.Multicomponent reactions have attracted the interest of polymer chemists and material scientists because of their special advantages(atomic economy,high efficiency,unique product properties,etc.).Multicomponent reactions can be used to synthesize new single molecules with multiple functional groups by connecting multiple substrates in one step,which greatly improves the efficiency of synthesis and endows the molecules with unique characteristics.Therefore,multicomponent reactions have advantages in the preparation of new multifunctional molecules.The introduction of multicomponent reaction into polymer synthesis,combined with free radical polymerization,and using the"one pot" strategy,the polymerization could introduce multifunctional groups at the same time,and obtain new multi-functional polymers via one-step synthesis.In this work,the precursor polymer was synthesized by "one pot" method,combining Kabachnik-Fields multicomponent reaction(K-F reaction)and free radical polymerization,and then the multifunctional polymer containing phenylboric acid group and a-aminophosphoric acid group with negative charge was prepared by a effective hydrolysis method.The boronic acid group on the side chain of the polymer can form poly anion self healing hydrogels through a dynamic borate ester bond with polyvinyl alcohol under mild conditions.The results showed that the hydrogel had low cytotoxicity and the hydrogel could be used for three-dimensional cell culture.In this paper,we selected positive-charged-cisplatin as a model drug,and studied the cumulative release from the hydrogel.The negatively charged ?-aminophosphoric acid group in the hydrogel effectively combined with positively charged cisplatin,which reduced the release rate of the drug and significantly improved the cell safety of cisplatin.This indicates that the hydrogel can be used as a drug delivery system for clinical treatment.In addition,due to the lack of research on ?-aminophosphoric acid group,we also designed a model molecule experiment and proved the binding between ?-aminophosphoric acid group and cisplatin.