Recent Advances on Bioprinted Gelatin Methacrylate-Based Hydrogels for Tissue Repair

Bioprinting of body tissues has gained great attention in recent years due to its unique advantages, including the creation of complex geometries and printing the patient-specific tissues with various drug and cell types. The most momentous part of the bioprinting process is bioink, defined as a mixture of living cells and biomaterials (especially hydrogels). Among different biomaterials, natural polymers are the best choices for hydrogel-based bioinks due to their intrinsic biocompatibility and minimal inflammatory response in body condition. Gelatin methacryloyl (GelMA) hydrogel is one of the high-potential hydrogel-based bioinks due to its easy synthesis with low cost, great biocompatibility, transparent structure that is useful for cell monitoring, photocrosslinkability, and cell viability. Furthermore, the potential of adjusting properties of GelMA due to the synthesis protocol makes it a suitable choice for soft or hard tissues. In this review, different methods for the bioprinting of GelMA-based bioinks, as well as various effective process parameters, are reviewed. Also, several solutions for challenges in the printing of GelMA-based bioinks are discussed, and applications of GelMA-based bioprinted tissues argued as well. Impact statement Bioprinting has been demonstrated as a promising and alternative approach for organ transplantation to develop various types of living tissue. Bioinks, with great biological characteristics similar to the host tissues and rheological/flow features, are the first requirements for the successful bioprinting approach. Gelatin methacryloyl (GelMA) hydrogel is one of the high-potential hydrogel-based bioinks. This review provides a comprehensive look at different methods for the bioprinting of GelMA-based bioinks and applications of GelMA-based bioprinted tissues for tissue repair.