A REVIEW ON THE HYDROGELS USED IN 3D BIO-PRINTING

The bio-printing process describes as a computer-aided transfer process for printing of biological structures such as cells and biomaterials to fabricate medical constructions for different medical fields (tissue engineering, regenerative medicine, or other biological studies). Especially, three-dimension (3D) bio-printing technology is used to print living organs like livers, kidneys, lungs, and any other organs in the body. Hydrogels have been widely used in 3D bio-printing to load cell for tissue engineering due to their high biocompatibility. In addition, hydrogels simulate the soft tissues which present in the body, swollen in water at high levels and have similar mechanical properties to those of natural soft tissues, many researchers have been interested in hydrogels and their reputations are increasing day by day. They are generally divided into two groups as (i) natural hydrogels and (ii) synthetic hydrogels. Key documents in the literature about both natural and synthetic hydrogels have been reviewed in this study. Also, 3D bio-printing process of the hydrogels has been discussed as detailly