[Experimental study and application of extracellular matrix of conjunctiva]

To investigate the characteristics and application of extra-cellular matrix (ECM) of conjunctiva.

Pieces of conjunctival ECM were made, and then the conjunctival defect was repaired with that in an experimental group. Control group 1 received the heterogeneous conjunctiva, and in control group 2, the refrigerated ECM was used for transplantation. All of them were photographed and examined by light microscope, electron microscope (EM), immunohistochemical examination and lymphocyte toxicity test.

There were blood vessels growing into the grafts on the 3rd day in the experimental group. The grafts became mildly congestive and similar to normal conjunctival ones in the 4(th) week. But in control group 1, the grafts became white and necrotic in the second week; the conjunctiva was congestive, cicatricial and hyperplastic in the 4(th) week. Under the light microscope, the epithelium covered the most part of the region with the graft in the 2nd week, covered completely in the 4(th) week, and its appearance was as an approximately normal conjunctival epithelium in the experimental group. But the epithelium became ulcerative and a lot of lymphocytes infiltrated in the 2nd week in control group 1. Under the EM, the line of demarcation between the covering region of the regenerative conjunctival epithelium and the naked ECM was quite clear in the 1st week in the experimental group. And the ultrastructure of regenerative conjunctival epithelium was basically the same as an normal one in the 8(th) week. Both before and after transplantation, the immunohistochemical examinations verified that ECM was type I and IV collagen. The lymphocyte toxicity test showed that no obvious humoral immunoreaction existed.

Conjunctival ECM has the characteristics of tissue activity and low antigenicity. It is an ideal conjunctival succedaneum in the plastic surgery of conjunctiva.