Abstract
Abstract: :
Purpose: To prepare a bioengineered ocular surface tissue replacement to include (presumed) human corneal epithelial stem cells in a crosslinked fibrin gel for potential transplant. Methods:Human epithelial stem cells (presumed) were harvested, isolated and cultivated as previously described from adult donor corneae obtained from the Sierra Regional Eye & Tissue Donor Services of Dialysis Clinics Inc. The cultured corneal epithelial stem cells were suspended in a fibronectin/fibrin gel cross linked by thrombin and factor XIII. All plasma components were obtained from ThermoGenesis, Inc. as a fibrinogen-rich cryoprecipitate of human plasma. Suspended cells proliferated in the fibrin gel, giving rise to colonies that eventually coalesced to near confluence over the 15 days of cultivation. The gels were sectioned and immunostained for Keratin 3 (AE5) and 19. Results:The fibrin gel product with corneal stem cells was easily manageable and maneuverable. Addition of the protease inhibitor, aprotinin, to the incubation medium, prevented gel degradation; once removed, gels disintegrated within 24 hours. All of the cells cultivated in the fibrin gel stained positively for Keratin 3 (AE5) indicating differentiation along the corneal epithelium lineage. Cells located in the center of the colonies were Keratin 19 positive suggesting a more primitive cell type. Growth kinetics were documented. Conclusion: A bioengineered ocular surface with a combination of presumed corneal epithelial stem cells in a crosslinked fibrin gel represents a potential improvement in current attempts to create a transportable, pliable and stable tissue replacement. Since both the cells and the plasma components of the fibrin gel are of human origin, this technique provides the potential for a totally autologous bioengineered replacement tissue. Supported in part by an unrestricted grant from Research to Prevent Blindness, NY and NIH core grant # P30EY12576.
Keywords: 372 cornea: epithelium • 370 cornea: basic science