Nerve regeneration in liquid cornea patches

Abstract

AbstractIn current clinical practice, corneas with perforations that are repaired by cyanoacrylate gluing and those with recurrent ulcerations are often treated by corneal grafting as the treatment to restore vision. However, there is a severe shortage of donor corneas worldwide. More importantly, when someone has a toothache and visits the dentist, the dentist removed the pathologic portions and fills the tooth. Corneal transplantation for a perforation or ulcer would be similar to extracting the tooth and replacing with an implant. Our objective was to develop a method for restoring pathologic corneas such as those with ulcers or perforations that avoids corneal transplantation. We have developed a Liquid Cornea Patch (LCP) that is based on a collagen‐like peptide conjugated to a polyethylene glycol backbone. The LCP is applied as a viscous liquid that polymerises in situ to form a hydrogel. We previously reported its efficacy in sealing large perforation in vitro (Samarawickrama et al. 2018). We also showed that the crosslinking agent used was non‐toxic to corneal epithelial and endothelial cells at doses used for hydrogel formation. Here, we report on a second‐generation patch which we successfully tested in vivo in rabbit and mini‐pig corneas. The LCP withstands bursting pressures up to 170 mm Hg. Although not as strong as cyanoacrylate glue, the bursting pressure is much higher than would be encountered in the human eye (where normal intraocular pressure is between 12 and 22 mm Hg). Over 12 months in mini‐pig corneas, the LCPs promoted regeneration of cornea tissue and nerves. We show that nerve in‐growth proceeded as per solid versions of collagen and collagen‐like peptide‐based implants.