Topical treatment of corneal alkali burns with Gly-thymosin β₄ solutions and in situ hydrogels via inhibiting corneal neovascularization and improving corneal epidermal recovery in experimental rabbits.

Abstract

Corneal alkali burns are a severe disease and commonly encountered in the emergent clinic. A rapid medical treatment for the burn is very important. Gly-thymosin β₄ (Gly-Tβ₄) is a biomimic derivative of natural thymosin β₄. The aim of this study is to evaluate the corneal recovery effects of Gly-Tβ₄ topical therapy on alkali burns in rabbit corneas. Rabbit alkali burns were induced with NaOH-contained filter paper. Phosphate-buffered solutions at pH 7.0, Gly-Tβ₄ solutions, blank in situ hydrogels, and Gly-Tβ₄in situ hydrogels were dropped on the burned corneas. The treatments were continued for 14 days. Conjunctiva hyperemia, corneal edema, intraeye extravasation, hemorrhaging, corneal neovascularization (CNV), and corneal opacity were observed. Corneal immunohistochemistry and histopathology were performed. Gly-Tβ₄ solutions led to a lower corneal burn index than the other regimens. Hydrogels may stimulate the burned corneas due to the direct contact of them, and prevent the rapid release of Gly-Tβ₄. Gly-Tβ₄ significantly inhibited CNV according to the images of the corneas, CNV areas, and CD31 expression. Furthermore, Gly-Tβ₄ improved corneal epidermal recovery according to the histopathological result. Gly-Tβ₄ solutions are a promising formulation for topical treatment of corneal alkali burns.