Biobased photocrosslinkable gelatin-methacrylate hydrogels promote the growth and phenotype maintenance of human corneal keratocytes

Abstract

Light-initiated crosslinking of hydrogels is a promising approach for the controlled fabrication of 3D environments in tissue engineering. One of the most fundamental challenges to overcome in light-based hydrogel systems is to maintain high cell viability and phenotype conservation while also minimizing the negative impact of photoinitiation systems on the environment. In this study, a novel photocrosslinkable hydrogel system based on gelatin methacryloyl, and using riboflavin and arginine as natural photoinitiator and co-initiator, respectively, (RA-GelMA) is reported. Photocrosslinking of RA-GelMA is induced by visible light, and the gelation point can be adjusted between 42 and 300 s by changing the concentration of co-initiator or polymer. Depending on the co-initiator concentration, irradiation time, and irradiation intensity, gels with a storage modulus between 2.5 and 17 kPa are produced. Sustained in vitro culture of both immortalized and primary human corneal keratocytes as well as cell spreading and phenotype maintenance of primary human corneal keratocytes can be achieved by optimizing the arginine concentration and the irradiation time. This study contributes to the development of sustainable and cell-friendly hydrogel systems as alternatives to state-of-the-art light-triggered hydrogel systems, which are based on synthetic photoinitiators such as LAP or Irgacure, promising for corneal tissue engineering.