Study On Biocompatibility And Neural Regeneration Of 10mm Diameter Xenogeneic Corneal Stroma In Vivo.

Objective: To study histocompatibility, immunocompatibility, and nerve regeneration of the 10mm diameter fresh and dehydrated xenogeneic corneal stromas in a model of xenotransplantation.Methods: (1) The fresh and dehydrated grafts of 10mm in diameter from the porcine corneal stroma were implanted intralamellarly in corneas of 12 New Zealand rabbits (n=6). Clinical observation and histopathologic observation were performed for five months after intracorneal implantation. The process of nerve regeneration in the corneal stromas of the 12 hosts was observed at one month intervals following the surgery through the silver nerve staining technique. (2) Twenty-four mice were randomly divided into 4 groups. The fresh and dehydrated corneal stromas of 10mm in diameter from porcine corneas were subcutaneously implanted into the mice of experimental groups (n=6). The xenogeneic dermas implantation mice and xenogeneic amniotic membrane implantation mice were taken as the positive and negative control groups (n=6). Clinical observation was performed. The lymphocytes from the peripheral blood of 24 hosts were immunologically labeled by anti-mouse-CD4-FITC, anti-mouse-CD8-PE, and anti-mouse-CD3-PE-Cy5, then determined by flow cytometry at 15^th day and 30^th day after hetertopic transplantation. Grafted xenogeneic materials were excised 30 days post grafting for histopathologic study, and the changes of total T lymphocyte and its subset counts in the xenografts were observed using the direct immunofluoresecent technique.Results: (1) In the rabbits of experimental groups, all the xenogeneic corneal grafts were survived without reject reaction. The fresh grafts got transparent after 1 month, and the dehydrated grafts got transparent after two months. Histological study demonstrated both the fresh and dehydrated corneal stroma grafts had healed with rabbits' corneal stroma very well without lymphocytes infiltrating. The regenerative nerves in the host corneas grew respectively into the fresh grafts adjacent to the incision site after two months and into the dehydrated grafts after three months, but they were abnormal in both distribution and morphology. After four months, at both...