Using acellular porcine limbal stroma for rabbit limbal stem cell microenvironment reconstruction

To investigate the feasibility of using acellular porcine limbal stroma for limbal stem cell microenvironment reconstruction. Limbal reconstruction was performed in rabbit partial limbal defect models. Rabbits were randomly divided into four groups: acellular porcine limbal stroma, de-epithelized rabbit limbal autograft stroma, de-epithelized porcine limbal stroma and acellular porcine corneal stroma transplantation groups. In both the acellular porcine limbal stroma and de-epithelized rabbit limbal autograft stroma groups, cornea transparency and epithelium integrity were sustained and graft rejection was not observed. The basal epithelial cells of the grafts showed the K3+/P63+/Ki67+ phenotype at postoperative month 1, but it returned to K3-/P63+/Ki67+(phenotype characteristic of limbal epithelium) by postoperative months 3 and 6. In the de-epithelized porcine limbal stroma group, acute and serious immune rejection occurred by postoperative days 8-10. The basal epithelial cells of the grafts showed the K3+/P63+/Ki67+ phenotype at postoperative month 1. In the acellular porcine corneal stroma group, there were some new vessel invasion into the peripheral cornea and mild corneal opacity. The basal epithelial cells of the grafts showed the K3+/P63+/Ki67+ phenotype at postoperative months 1, 3, and 6. In conclusion, acellular porcine limbal stroma possessed very low immunogenicity, retained a good original limbal ECM microenvironment, and thus the reconstructed rabbit limbal microenvironment maintained limbal epithelial stem cell stemness and proliferation.