ABSTRACT
Background Corneal blindness caused by ocular surface disease is one of the main reasons for the global blinding corneal diseases.With the development and progress of tissue engineering technology,tissueengineered cornea offers a new approach to the treatment of ocular surface disease.Objective This study was to obscrve the growth and differentiation of human umbilical cord mesenchymal stem cclls (UC-MSCs) on thc corneal stroma of receipts and investigate the feasibility of human UC-MSCs differentiated into corneal epithelium-like cells and the reparation of injury cornea.Methods Human UC-MSCs were isolated from human umbilical cord using collagenase Ⅳ digestion and passaged in DMEM/F12 containing fetal bovine serum in vitro.The immunophenotype of cultured human UC-MSCs was evaluated by flow cytometry.The differentiated osteoblasts from the human UC-MSCs by directional induce was identified.Twenty-four New Zealand albino rabbits were randomly divided into 2 groups.The human UC-MSCs were cultured on porcine corneal matrix without corneal epithelium for 4 days and then transplanted onto the 12 left eyes of 12 New Zealand albino rabbits,and porcine corneal matrix without corneal epithelium was transplanted onto the left eyes of other 12 New Zealand albino rabbits as control group.The rabbits received keratoplasty were examined using in vivo confocal microscope through focusing(CMTF).The eyeballs were taken off after 2,4 and 8 weeks,the growth and differentiation,expression of cytokeratin 3 (CK3),CK12 and ATP-binding cassette superfamily G memben 2 (ABCG2)of human UC-MSCs were observed by histopathology and immunofluorescence staining.This use of the experimental animals complied with ARVO Statement.Results Digestive human UCMSCs formed round in shape and was large in size.The attached cells displayed long-fusiform shape like fibroblasts.The cultured human UC-MSCs phenotype was CD105+/CD29+/CD44+/CD34-/CD45-and could be induced toward osteoblast differentiation under the appropriate experimental conditions.Human UC-MSCs grew well on the porcine corneal matrix.The corneal grafts survived wcll without rejection till the experiment end in experimental eyes,but the rejection of corneal graft occurred in control eyes.Confocal microscope could observe corneal epithelium-like cells.The corneal epithelium cells showed the positive response for CK3 and CK12 and absent response for ABCG2.Conclusions Human UC-MSCs with porcine corneal matrix can survive,proliferate and differentiate into corneal epithelium-like cells after transplanting onto the corneal stroma of rabbits.This result suggests that human UC-MSCs is able to repair and reconstruct the injured corneal surfaces.