Patent ID: 8642338

Claim:
An in vitro anterior ocular segment comprising a cell sheet having at least 80% of both intercellular desmosome structure and basement membrane-like protein intact produced by a process comprising: (a) culturing cells selected from the group consisting of corneal epithelial cells, corneal endothelial cells, conjunctival epithelial cells, and epithelial stem cells on a cell culture support to form a cell sheet, wherein the surface of said cell culture support is covered with a temperature responsive polymer with an upper or lower critical solution temperature between 0-80° C. in an aqueous solution and wherein coverage of the temperature responsive polymer on the surface of said cell culture support is in the range of 0.3-6.0 μg/cm 2 ; (b) contacting the cell sheet from (a) with a polymer membrane on the opposite side from said cell culture support until the cell sheet adheres to the polymer membrane, wherein the polymer membrane is capable of being easily stripped from the cell sheet after adherence and wherein the polymer membrane is selected from the group consisting of polyvinylidene difluoride (PVDF), polypropylene, polyethylene, cellulose, cellulose derivatives, chitin, chitosan, collagen, and urethane; (c) detaching from said cell culture support the cell sheet with the polymer membrane adhered thereto from (b) by either increasing the temperature above the upper critical dissolution temperature or decreasing the temperature below the lower critical dissolution temperature, wherein the detaching is without subjecting the cell sheet or said cell culture support to any treatment with a proteinase; and (d) stripping the polymer membrane from the cell sheet from (c) to obtain a cell sheet having at least 80% of both intercellular desmosome structure and basement membrane-like protein intact.