Abstract
Purpose :
Artificial cornea substitutes that allow rapid epithelial cell migration reduce the risk of rejection, corneal melting and scarring. In this study, we developed an ex vivo corneal tissue culture model to better represent the in vivo reepithelialization process, and the biocompatibility of different collagen-based artificial corneal substitutes were evaluated in this model.
Methods :
Different types of collagen-based corneal substitutes were fabricated by crosslinking type I collagen by EDC-NHS (Col-CXL); gelling collagen solution in ammonia vapor followed by vitrification (AMC). Negative control was a collagen based formulation that was previously proved to support epithelial cell growth in vitro, but rejected in animal study. Rabbit corneal explants were wounded with 6 mm biopsy punch, and different corneal substitutes were placed under the wounded corneas to allow cell migration. The reepithelialization was observed with fluorescein staining, and the epithelial multilayer and tight junction formation was characterized by histology and immunohistochemistry.
Results :
This ex vivo model allowed epithelial cell migration on different types of corneal substitutes. Fluorescein staining presented epithelial cell migration started in the first 24 hours, and full reepithelialization completed on CXL-Col and AMC in 48 hours, while the negative control showed no significant progress. Hematoxylin and eosin (H&E) staining presented multilayer formation (Fig. 1) on the Col-CXL and AMC corneal substitutes. The migrated corneal epithelial cells of the ex vivo model were sensitive to different substrates, as evidenced by the formation of tight junction and the expression of epithelial cell specific markers.
Conclusions :
Conclusions: The ex vivo corneal tissue culture model demonstrated the similarity of the wound healing process in vivo. The material sensitivity of this biological model allows a better evaluation of biocompatibility of corneal substitutes. Moreover, the use of our ex vivo model will enable further evaluations of mechanisms of reepithelialization and wound healing process before animal testing.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.