Using basement membrane of human amniotic membrane as a cell carrier for cultivated cat corneal endothelial cell transplantation

Purpose: To study the feasibility of using basement membrane of human amniotic membrane (BMHAM) as a carrier for transplantation of cultivated cat corneal endothelial cells (cCCECs). Methods: BHMAM was obtained by enzymic digestion. cCCECs were seeded on the BMHAM and cultivated traditionally. The resulting continuous monolayer of cCCECs was transplanted onto the cat corneal graft stripped of the Descemet membrane with endothelium. To determine whether the transplanted cCCECs were vital and functional in vivo, the corneal grafts were examined by slit-lamp microscope every day for 6 weeks, and corneal thickness was measured by ultrasonic pachymetry. Either in vivo or in vitro, the cCCEC sheets on BMHAMs were examined morphologically by light and electron microscope, and the cell density was measured. Results: Seven to 10 days after seeding on the BMHAM, the cCCECs were confluent and formed a continuous monolayer with 3486 +/- 53 cells/mm(2) cell density. Like normal corneal endothelial cells, the cCCECs were almost hexagonal, squamous, and uniform in size. After transplantation, most cells were vital and functional nearly enough to maintain corneal graft thickness and transparency without rejection of at least 6 weeks. Six weeks after operation, the average thickness of the transplanted corneal grafts was only slightly greater than that before operation. Compared with that in vitro, after transplantation there was 5% to 8% reduction per week in cell density, which lasted for almost 3 weeks. After that, the average cCCEC density of corneal grafts was 2837 +/- 57 cells/mm(2) and quite stable maintained. Conclusion: This study demonstrated that BMHAM would be an ideal alternative for corneal Descemet membrane and a cell carrier for cCCEC transplantation.