Visible Light-Induced 3D Bioprinting Technologies and Corresponding Bioink Materials for Tissue Engineering: A Review

Three-dimensional (3D) bioprinting based on traditional 3D printing is an emerging technology that is used to precisely assemble biocompatible materials and cells or bioactive factors into advanced tissue engineering solutions. Similar technology, particularly photo-cured bioprinting strategies, plays an important role in the field of tissue engineering research. The successful implementation of 3D bioprint-ing is based on the properties of photopolymerized materials. Photocrosslinkable hydrogel is an attractive biomaterial that is polymerized rapidly and enables process control in space and time. Photopolymerization is frequently initiated by ultraviolet (UV) or visible light. However, UV light may cause cell damage and thereby, affect cell viability. Thus, visible light is considered to be more biocom-patible than UV light for bioprinting. In this review, we provide an overview of photo curing-based bio-printing technologies, and describe a visible light crosslinkable bioink, including its crosslinking mechanisms, types of visible light initiator, and biomedical applications. We also discuss existing chal-lenges and prospects of visible light-induced 3D bioprinting devices and hydrogels in biomedical areas. (C) 2020 THE AUTHORS. Published by Elsevier LTD on behalf of Chinese Academy of Engineering and Higher Education Press Limited Company.