【作者】 李静；

【导师】 李丽；

【作者基本信息】 兰州大学 ， 眼科学， 2007， 硕士

【摘要】 目的：眼部整形手术需要多种修复材料，保存的异体巩膜是最常应用的材料之一，但同种异体巩膜来源有限，费用相对较高，没有眼库的医院，人体巩膜组织无从获得。而且异体巩膜移植有传染疾病的危险，因此眼科整形手术需要寻找更易的、更厚韧、更经济的理想材料。异种(猪)脱细胞真皮基质(acellular xenogenic dermal matrix，Xeno-ADM)是异种猪皮经特殊处理，去除其细胞成分后得到的一种真皮替代品。在异种(猪)脱细胞真皮基质的制作工艺中，去除表皮和细胞，去除组织抗原性，在真皮乳头层表面，保留了完整、连续的基底膜和真皮中胶原束结构，使其排列正常，弹力纤维正常存在。异种(猪)脱细胞真皮基质是近年来整形领域的重点研究项目。本研究进行异种脱细胞真皮基质替代睑板在兔眼睑缺损模型中进行眼睑原位重建术的动物实验，从组织学和细胞学水平研究获得可行性依据以证明异种脱细胞真皮基质可以作为睑板替代物应用于临床，为异种脱细胞真皮基质在眼部整形和外伤修复的推广应用提供依据。方法：36只新西兰大白兔随机分为两组，制作兔眼睑缺损动物模型，随机分别给予异种脱细胞真皮、兔巩膜(异体巩膜)行眼睑原位重建术。活体观察动物术后情况和移植物情况，于术后1、2、4、6、8和12周，取带植片(异种脱细胞真皮和异体巩膜)的眼睑，光镜下观察替代材料和自体睑板交界处的组织病理学改变，包括炎症反应、纤维血管化情况和融合情况。并取4、8和12周标本做透射电镜观察上述组织的超微结构改变。结果：1．异种脱细胞真皮与异体巩膜作为睑板替代物进行眼睑原位重建术后，大体观察二者反应类似，Xeno-ADM较异体巩膜炎症反应小，术后炎症反应消退较快，术后未见植入物暴露、脱落和感染现象，肉眼见血运良好无坏死，受体结膜可在植入体(猪脱细胞真皮或兔异体巩膜)表面爬行生长。2．光镜下观察Xeno-ADM在2周时移植物与兔自身睑板胶原组织的分界已不十分明显，并开始出现成纤维细胞和少量毛细血管。8周时移植物内可见增生的小血管和神经纤维团，交界不清逐渐过渡，12周时不能区分移植物和原组织胶原成分，脱细胞真皮自身的胶原纤维排列失去方向性，其间可见增生的小血管和神经纤维小管。异体巩膜组4周时才见新生血管和成纤维细胞，6周时仍可见少量淋巴细胞和浆细胞浸润。两组比较，Xeno-ADM在1、2、4、6、8w较异体巩膜组炎症反应消退快，血管化快，新生胶原长入快。12周时镜下表现基本类似，无显著差异。3．电镜下两组变化类似，4周时自体睑板与植入体已无明显界限，胶原纤维结构清晰，周期性横纹明显，纤维间可见到新生的毛细血管、神经及正在吞噬成纤维细胞的巨噬细胞。8周时可见到大量功能活跃的成纤维细胞，细胞质内有丰富的粗面内质网及多聚核糖体，粗面内质网呈池样扩张，扩张的池内含有蛋白样物质，成纤维细胞周围有许多均质的蛋白样物质。12周时自体睑板与植入体无明显界限，胶原纤维排列不整，横纵交错，其间可见到凋亡细胞、凋亡小体和神经纤维。胶原原纤维周期性横纹整齐，结构清晰。结论：1．异种脱细胞真皮与异体巩膜作为睑板替代物，两者大体观察无显著差异，组织病理学变化和免疫反应相似。从形态学上大致分为三个阶段：炎症反应阶段(植入后1-2周)、细胞浸润及纤维血管长入阶段(植入后2周-2月)、瘢痕组织形成阶段(植入后2-3月)。2．Xeno-ADM在眼睑重建代替睑板手术中，较异体巩膜炎症反应小而且术后炎症反应消退快，未见植入物暴露、脱落和感染现象，血运良好无坏死，受体结膜可在脱细胞真皮表面爬行生长。3．Xeno-ADM作为睑板修补材料，具有一定的弹性、韧性，与自体睑板结构类似、功能类似、颜色接近。愈合后接近正常睑板，能和植床永久性粘连，愈合紧密，术后反应轻微，无明显的移植排斥反应。总之，Xeno-ADM作为支撑物，保留了胶原纤维和小血管的基质成分，可以引导受体细胞，新生血管和新生胶原的长入，从而使移植物和受体密切愈合成为一体。因而有望成为一种优良的生物支架应用于眼睑成形术。更多还原

【Abstract】 ObjectiveThe ophthalmol plastic reconstruction surgery needs various kinds of repairing materials; the reserved allogeneic sclera is one of the most popularly used materials. However, the allogeneic sclera source is limitied, the application cost is relatively high, and it is hard to obtain the sclera from hospitals without eye banking facilities. In addition, the allogeneic sclera transplant has the risk of infection. Therefore it is necessary to seek a more economical for the ophthalmol plastic reconstruction surgery.The acellular xenogeneic dermal matrix (Xeno-ADM) is a kind of dermis substitute obtained from xenogeneic porcine skin with special handling to remove its cell components. During the manufacturing process of Xeno-ADM, the epidermis, the cell and the antigenicity are removed; the complete and continued basement membrane and dermis collagen network were kept in the papillary layer to keep its normal arrangement and tension fiber. The Xeno-ADM is one of the important research projects in recent years. This experiment focused on using Xeno-ADM to replace the tarsal cartilages in the analogue of rabbit eyelid defect and to perform the eyelid reconstruction in situ. With the evidence from the histology and cytology experiment, Xeno-ADM proved to be a substitute of palpebral cartilages for clinical use, which provides the verification to broaden the application of the Xeno-ADM in ophthalmology.MethodThirty-six New Zealand rabbits were divided into two groups randomly. Establishment of the rabbits unilateral eyelid defect model, the eyelid reconstruction in situ were performed with either acellular xenogeneic dermal matrix or allogeneic sclera at random. The rabbits were clinically examined for inflammation and impant exposure and sacrificed 1, 2, 4, 6, 8 and 12 weeks after implantation. The eyelid with implant ( Xeno-ADM or allogeneic sclera ) were dislodged and the specimens were assessed histopathologically and ultrastructually with light microscopies respectively for evaluation of change of juncture between implant and autoallergic tarsal plates including inflammation, vascularization and confluence. The 4, 8 and 12 weeks specimens were assessed with transmission electron microscope micro structural changes of the above organizations.Results1. When the eyelid reconstruction in situ were performed with either acellular xenogeneic dermal matrix or allogeneic sclera, there were similar reaction and change between them. But Xeno-ADM as repairing materials, it invokes more little immunological and inflammatory reaction than that of the allogeneic sclera. Moreover, no implants shedding, exposure or infection happened postoperatively; good blood supply and no cellular necrosis. The conjunctiva grew well on the surface of the implant ( Xeno-ADM or allogeneic sclera).2. With the light microscopy, 2 weeks after implantation, the borderline between Xeno-ADM implant and autoallergic tarsal becomes fuzzy; while at the conjuction area, some complete capillary structure and a few fibroblasts were seen growing into the implant. 8 weeks after implantation, the borderline transitions gradually. Relatively larger new blood vessels were seen obviously growing at the center of the Xeno-ADM implant with complete endothelial cell in the blood vessels. 12 weeks after implantation, the arrange of the collagen network of the acellular dermal matrix lost the directivity, and both the vertically and the horizontally arranged new collagen could been seen; The new small vessels and proliferative neurofibra tubulus could been found among the Xeno-ADM implant. However, a few fibroblasts and small new vessels were only observed 4 weeks after implantation in allogeneic sclera group. At 1, 2, 4, 6 and 8 weeks after implantation, the inflammatory cells (neutral granular cells, uni-nuclear cells), the lymphocytes and the plasmocytes are less than those of the allogeneic sclera implants, and the blood vessel grows faster, the new collagen grows into implant faster. There is no statistical difference between two groups when the experiment ended.3. With the electron microscopy, histopathological change and cellular change in form of the Xeno-ADM are similar to those of the allogeneic sclera.Conclusion1. As the substitute of tarsal cartilages, when the eyelid reconstruction in situ were performed with either acellular xenogeneic dermal matrix or allogeneic sclera, there were similar histopathological and immunological change between them. This process could be divided into three stages (1) inflammation reaction stage (1-2 weeks after the implants ); (2) the cell infiltration and the textile fiber growth stage ( 2 weeks - 2 months after the implants ); (3) the scar organization production stage (2-3 months after the implants ).2. Xeno-ADM as repairing materials, as the support for eyelid’s soft tissue’s growth in the eyelid reconstruction in situ, it invokes more little immunological and inflammatory reaction than that of the allogeneic sclera. Furthermore, inflammatory reaction after operation regresses quickly; no implants shedding, exposure or infection happened postoperatively; good blood supply and no cellular necrosis. The conjunctiva grew well on the surface of the acellular dermal matrix.3. As the substitute of tarsus in supporting the eyelid, Xeno-ADM possesses flexibility and tenacity and resembles the construction, function and color of autoallergic tarsal. Graft rejective reaction doesn’t invoke obviously. Xeno-ADM and tarsus produced the new collagen to unite them with each other.In brief, as the substitute of tarsal cartilages, the Xeno-ADM retained the basic ingredients of the collagen fiber and the small blood vessel, which allows the host cells, the new blood vessel and the new collagen to grow into the eyelid to unite the transplant. Therefore, it can act as a superordinary biological scaffold to utilize in blepharop lasty .更多还原