Advances in Photocrosslinkable Materials for 3D Bioprinting
Suitable bioink plays a key role in 3D bioprinting. Photocrosslinkable biomaterial is a promising type of bioink for 3D bioprinting with unique characteristics, including facile crosslinking, improved mechanical property, and better printability. These photocrosslinkable bioinks are usually derived from proteins, polysaccharides, synthetic polymers, or decellularized extracellular matrix and crosslinked via radial coupling, thiol?radical reaction, or tyrosine dimerization mechanism.3D bioprinting integrating multidisciplinary advances in engineering, cell biology, and material science is able to fabricate artificial tissues and organ?like structures with biology or clinic?relevant size, shape, and structural integrity. Therefore, 3D bioprinting has huge potential in tissue engineering and regenerative medicine. Suitable bioink plays a key role in the modulation of the printing process, the properties, and functions of printed constructs. Herein, the advances in photocrosslinkable biomaterials are focused on, which have been proven as promising types of bioinks for 3D bioprinting. The general strategies of 3D bioprinting and the main mechanisms involved in photocrosslinking are first discussed. Then, the recent advances in photocrosslinkable bioinks including natural protein? and polysaccharide?based materials, synthetic polymers, and decellularized extracellular matrix (dECM)?based materials are highlighted. Finally, the ongoing challenges in the delicate balance between the printability and biological activities of photocrosslinkable biomaterials are discussed and the outlook for this emerging area is analyzed.