Preparation and characterization of double crosslinked hydrogel films from carboxymethylchitosan and carboxymethylcellulose

• Carboxymethylchitosan (CMCS)/carboxymethylcellulose (CMC) hydrogel film was prepared.
• Ionical crosslinking with CaSO4 and covalent with genipin was combined to form film.
• The significant difference of mechanical properties of hydrogel films was analyzed.
• The biocompatibility of the crosslinked hydrogels was comparatively confirmed.

A novel crosslinked hydrogel film was prepared from carboxymethylchitosan (CMCS) and carboxymethylcellulose (CMC) by ionical and covalent crosslinking with CaSO4 and genipin, respectively. The swelling ratio of the crosslinked CMCS/CMC hydrogel films was investigated at different pH solutions (1–9), and the results indicated that the crosslinked hydrogels had the swelling–deswelling properties with two primary peaks of swelling ratio at pH 3 and 7. The surface morphologies of the crosslinked hydrogels at different pH values provided evidences of the swelling–deswelling properties. The mechanical properties of the hydrogel films were also examined. The ionical and covalent crosslinking were found to have the primary impact on the toughness and max load, respectively, of the crosslinked hydrogels. The cells comparatively cultured on the crosslinked hydrogels and the negative and positive controls suggested the biocompatibility of the crosslinked CMCS/CMC films. This kind of hydrogel films have potential application in drug delivery vehicles and skin tissue engineering.