Preclinical study in a corneal bioreactor of the effectiveness of amniotic membrane of umbilical cord extract (AMUCE) for the treatment of corneal epithelial ulcerations

Abstract

AbstractPurposeOur patented corneal bioreactor (BR) improves the survival of human corneas ex vivo in the long term by restoring intraocular pressure and renewal of storage medium in a sterile environment.AimTo use the BR to test the efficacy of eye drops containing devitalized ground amniotic membrane of umbilical cord extract (AMUCE) to treat epithelial ulcerations. AMUCE contains high level of proteoglycans, collagen and physiological growth factors.MethodsOnly pairs of human corneas were used to obtain best possible controls. They were either corneas discarded by our eye bank (cell density between 800 and 2000 cells/mm2) or specific donation for research (normal corneas). They were first stored for 2 weeks into the BR filled with CorneaMax (Eurobio, France), with 21 mmHg in the endothelial chamber to allow regeneration of a normal epithelium as previously shown. Then, a 6.0 mm diameter calibrated epithelial ulcer was made. Using a specific BR lid allowing sterile handling, each cornea was treated topically 3 times daily either by the AMUCE eye drops (TBF, France) or by the vehicle (0.9% NaCl). Closure of the ulceration was monitored daily using fluorescein staining quantified by image analysis (FIJI) of macro‐zoom microscopy. After wound healing corneas were fixed for histology (Hematein Eosin Saffron) and immunolabeling of epithelial markers.ResultsThree pairs were used. Wound healing was obtained at D3, D7, D5 with the AMUCE and D3, D6, D6 with the vehicle (no significant difference). Nevertheless, drug‐treated corneas had a thicker epithelium than with vehicle only. Histology and immunolabeling for E‐Cadherin and cytokeratin K3/K12 confirmed that epithelium of AMUCE‐treated corneas was more differentiated than with vehicle only.ConclusionsThe BR allows controlled studies of epithelial wound healing on human corneas with repeated instillations. By improving epithelial maturation, AMUCE eye drop is an interesting candidate for epithelium regeneration.