结膜细胞外基质移植的实验研究与临床应用

摘要

目的观察结膜细胞外基质 (extracellular matrix, ECM)作为结膜组织的替代材料用于结膜成形的特点及临床疗效。方法将30只兔制作结膜缺损模型，并将其随机分为3组，实验组兔结膜采用组织工程技术制备的结膜ECM行结膜移植修补术，对照Ⅰ组采用新鲜异体结膜移植，对照Ⅱ组采用深低温冷冻的异体结膜，以观察移植修补术后结膜成形的情况，并行镜下、免疫组化及淋巴细胞毒检查。同时将结膜ECM应用于7例烧伤后睑球粘连患者，行结膜囊成形+结膜ECM移植术，观察其疗效。结果动物实验组，结膜 ECM移植后1周可见新生血管自移植片边缘长入，8周时外观已接近正常结膜，无免疫排斥反应；光镜下可见移植后4周时的移植区上皮已接近正常结膜上皮；电镜下，术后8周可见再生的结膜上皮细胞超微结构与正常结膜上皮细胞基本一致。对照Ⅰ组术后2周时，移植片可见大量炎性细胞浸润。对照Ⅱ组术后4周时，移植区仍有部分上皮未覆盖。7例患者结膜 ECM移植术后1～2周可见新生血管长入植片；2个月时，结膜组织与正常球结膜组织相近。术后随访9～26个月，平均18.3个月，结膜ECM植片存活良好，睑球粘连明显改善，已形成穹隆部，移植区结膜基本恢复正常颜色。结论结膜ECM为目前理想的结膜替代材料。%Objective　To investigate the characteristics and application of extra-cellular matrix (ECM) of conjunctiva. Methods　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. Results　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 4th 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 4th 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 4th 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 8th 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. Conclusion　Conjunctival ECM has the characteristics of tissue activity and low antigenicity. It is an ideal conjunctival succedaneum in the plastic surgery of conjunctiva.