Methacrylated gelatin hydrogels as corneal stroma substitutes: in vivo study

Abstract

Methacrylated gelatin (GelMA) hydrogels were prepared to serve as corneal stroma equivalents. They were highly transparent (ca. 95% at 700?nm), mechanically strong and withstood handling and had high human corneal keratocyte viability (98%) after 21?days of culture period. In order to test the in vivo performance of the cell free GelMA hydrogels a pilot in vivo study was carried out using eyes of two white New Zealand rabbits. Hydrogel was implanted in a mid-stromal pocket created and without suture fixation, and observed for 8?weeks under a slit lamp. No edema, ulcer formation, inflammation or infection was observed in both the control (sham) and hydrogel implanted corneas. Corneal vascularization on week 3 was treated with one dose of anti-VEGF application. Hematoxylin and Eosin staining showed that the hydrogel was integrated with the host tissue with only a minimal foreign body reaction. Results demonstrated some degradation in the construct within 8?weeks as evidenced by the decrease of the diameter of the hydrogel from 4?mm to 2.6?mm. High transparency, adequate mechanical strength, biocompatibility and well integration with the host tissue, indicates that this hydrogel is a viable alternative to the current methods for the treatment of corneal blindness and deserves testing on larger number of rabbits and more extensively using microscopy, histology and immune histochemistry.