DLP printing photocurable chitosan to build bio-constructs for tissue engineering.

In this study, we provide a photocurable chitosan bioink (CHI-MA), which can be used for the digital light processing (DLP) technology. The CHI-MA precursors were facilely synthesized by grafting chitosan molecular chains with methacryloyl groups. We investigated the effect of parameters, including the concentration and substitution degree (DS) of CHI-MA, on the rheology and the photocuring of bioinks and the mechanical property of photo-crosslinked gels. Using the CHI-MA with a high DS (33.6 %), the curing time to print a 150 μm thick hydrogel layer can be controlled within a reasonable short time period. Additionally, the cytotoxicity test shows that both the photocuring process and the photo-crosslinked hydrogels exhibit an excellent biocompatibility. Through the DLP printing, the CHI-MA bioink can be processed into complex 3D hydrogel structures with high-resolution, high-fidelity and good biocompatibility. It indicates that the photocurable CHI-MA would be a good bioink suitable for the DLP printing.