Effects of Gelatin Methacrylate Hydrogel on Corneal Repair and Regeneration in Rats

PURPOSE: This study investigates the repairing process of rat cornea after surgery of lamellar keratoplasty (LKP) and evaluates the effects of gelatin methacrylate (GelMA) hydrogel. METHODS: In the LKP group, the lamellar stroma matrixes of Sprague-Dawley rats were transplanted to enhanced green fluorescent protein rats, whereas those in the GelMA group were also embedded with a GelMA hydrogel during the corneal transplantation. Grafted eyes were harvested on days seven, 30, and 90. Hematoxylin and eosin staining, immunofluorescence staining, scanning electron microscopy, optical coherence tomography, and a slit-lamp microscope were used to study the process of corneal restoration and regeneration. RESULTS: A total of 42 rats were analyzed, including 18 rats in each of the experimental group and six rats in the control group. After three months, the infiltration degree of inflammatory cells differed between the LKP group and the GelMA group (P < 0.001). Moreover, in multiple comparisons in corneal thickness, significant difference was observed between the LKP group and the GelMA group. There was also divergence in the results between the LKP group and the control group (P < 0.001, P < 0.001). At the same time, the expression of α-smooth muscle actin (α-SMA) and transforming growth factor (TGF)-β1 varied distinctly between the LKP group and the GelMA group (P < 0.05, P < 0.001). CONCLUSIONS: Significant differences were demonstrated between the LKP group and the GelMA group in inflammatory cell infiltration, corneal thickness, as well as the expression of α-SMA and TGF-β1. Those differences indicate the ability of GelMA hydrogel to support alleviation in corneal stroma fibrosis and show the influences of fibrosis in the dysfunction of corneal refractive power. TRANSLATIONAL RELEVANCE: Our research provides new ideas for the future development of LKP and tissue-engineered corneas.