A photocurable hybrid chitosan/acrylamide bioink for DLP based 3D bioprinting

Chitosan-based hydrogel has been widely used in the field of tissue engineering due to its favorable biocompatibility and good biodegradability. However, this kind of hydrogel generally exhibits poor mechanical stability, which greatly limits its application in the field of 3D bioprinting. In this study, we provided a hybrid bioink created from photocurable chitosan and acrylamide (AM) for digital light processing (DLP) based 3D bioprinting in tissue engineering applications. This hybrid bioink was facilely prepared by combining AM and chitosan modified with methacryloyl groups (CHIMA). The gelling point of the hybrid pre-hydrogel bioink was greatly dependent on the photoinitiators. Both the mechanical properties and cytocompatibility of the hydrogel formed by the bioink can be modulated by varying the AM contents. The hybridization of natural CHIMA and synthetic AM enables the hybrid hydrogels with desirable biological activity and mechanical properties. Utilizing the DLP based 3D printing, this hybrid bioink can be processed into complex 3D hydrogel constructs with high-strength and good biocompatibility. Therefore, the photocurable hybrid bioink composed of CHIMA and AM in proper proportion is well suitable for use in DLP based 3D bioprinting, which would play a promising role in constructing tissues and organs in the future. ? 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).