Photocrosslinkable, thermoreversible, type-I collagen bioink for photolithographic printing

Biomedical engineers have leveraged a unique combination of properties of methacrylated collagen to demonstrate its potential as a bioink capable of simple, photolithographic printing of 3D scaffolds for tissue engineering and regenerative medicine. Type-I collagen is the most ubiquitous protein in the human body. Chief among the fibril forming collagens, type-I collagen gives many soft tissues strength and structure. Type-I collagen is also easily extracted from tissues, and it is frequently used as a 2D or 3D substrate for in vitro studies. Its ability to self-assemble hierarchically into strong and flexible fibers and its excellent biocompatibility across species also make it a popular biomaterial for applications in tissue engineering. However, its fibrillar, higher order structure also complicates collagen’s use as a bioink for 3D printing, which would otherwise be an increasingly popular approach to regenerative medicine.