Synthesis of an injectable, self-healable and dual responsive hydrogel for drug delivery and 3D cell cultivation

An injectable and self-healable hydrogel was synthesized using dynamic imine bonds as cross-links. The hydrogel was formed between glycol chitosan and a dibenzaldehyde terminated copolymer, poly(N-isopropylacrylamide)-co-poly(acrylic acid) (DF poly(NIPAM-co-AA)). The polymer gelator DF poly(NIPAM-co-AA) was synthesized by the polymerization of comonomers of NIPAM and AA using a dibenzaldehyde- terminated chain transfer agent (DF CTA). Besides its injectable and self-healable property, the hydrogel was also dual pH and temperature responsive following the properties of the polymer gelator, DF poly(NIPAM-co-AA). Drug-loaded hydrogels showed distinct release behaviours responsive to the surroundings of varied pH values and temperatures. Being non-cytotoxic, the hydrogel was also successfully applied for 3D cell cultivation of L929 cells, revealing the hydrogel's potential applications as carriers in drug delivery and cell therapy systems