Recent advances in the development of nature-derived photocrosslinkable biomaterials for 3D printing in tissue engineering

BACKGROUND: In recent years, three-dimensional (3D) printing has begun to be widely used in tissue engineering. Natural biomaterials have been employed to overcome the limitations of synthetic polymers. However, their low mechanical strength and poor printability are major disadvantages. Photocrosslinking is the most promising fabrication strategy because it is non-invasive and easy to control light intensity and exposure. In this article, developments of photocrosslinkable natural biomaterials in the field of 3D printing are reviewed. MAIN BODY: Photocrosslinkable biomaterials can be broadly classified into materials that use ultraviolet (UV) and visible lights. Many natural biomaterials such as gelatin, hydroxyapatite, silk fibroin, and pectin have been modified through acrylation, crosslinked by 365 nm UV light, and 3D printed. Riboflavin could also be used to crosslink and print collagen or decellularized extracellular matrix (dECM). In the case of silk-like aneroin and modified gelatin, crosslinking is possible by forming a dityrosine bond using 452 nm visible light. CONCLUSION: Despite the tremendous researches on the developments of photocrosslinkable 3D printing natural biomaterials, further efforts are necessary to develop source biomaterials with excellent biological functions and sufficient mechanical integrity.