Thermo/photo dual-crosslinking chitosan-gelatin methacrylate hydrogel with controlled shrinking property for contraction fabrication

Stimuli-responsive gel volume variation is reversible and has shown promising applications, which may be potential for contraction or expansion fabrication, generating shrinking or swelling volume of the original. In this study, a thermo/photo dual-crosslinking hydrogel is prepared with methacrylated hydroxylbutyl chitosan (MHBC) and gelatin methacrylate (GelMA). The M/G hydrogel undergoes sol-gel phase transition under room temperature and shrinking deformation upon elevating temperature. Besides nontoxicity and biodegradability, dual crosslink endowed the composite hydrogel with strengthened and tunable mechanical property, controlled and repeatable contraction property in response to temperature elevation from 25 degrees C to 37 degrees C, and enhanced cell adhesion in 3D culture. These peculiarities of M/G hydrogel provide great potential for application in contraction fabrication to acquire high resolution or small scale features that may be limited by fabrications devices.