Preparation and characterization of photo-oxidative dual-crosslinked chitosan/hyaluronic acid hydrogels

Here, photo-crosslinked CM/HM hydrogels and photo-oxidative dual-crosslinked CM/HM/CSD hydrogels (DH) were fabricated based on chitosan methacrylate (CM), aminoethyl methacrylated hyaluronic acid (HM) and chitosan-3,4-dihydroxybenzaldehyde (CSD). Two kinds of different substitution degree of CM and HM and one kind of CSD were prepared respectively by amidation. The chemical structures of CM, HM, CSD were determined using proton nuclear magnetic resonance ( 1 H-NMR) spectroscopy, fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV–vis) spectrum and differential scanning calorimetry (DSC). CM/HM hydrogels and DH with adjustable properties were obtained by adjusting the degree of substitution (DS) and the type of network. These hydrogels can be easily and quickly gelled in situ and all hydrogels had desirable swelling percentages and biodegradability. Furthermore, introduction of catechins enhanced the mechanical strength of hydrogels meanwhile improved the flexibility, and maintained the pore structure. These controllable hydrogels have great potential for tissue engineering applications. • Two kinds of hydrogels were formed via photo- and oxidative-crosslinking. • Easily and quickly gelled in situ. • The degree of substitution adjusted the properties of photo-crosslinked hydrogels. • Secondary covalent network formed by catechol improved the toughness.