Salzmann D L, Kleinert L B, Berman S S, Williams S K
Department of Surgery, Health Sciences Center, University of Arizona, Tucson 85724, USA.
J Biomed Mater Res. 1997 Mar 15;34(4):463-76. doi: 10.1002/(sici)1097-4636(19970315)34:4<463::aid-jbm7>3.0.co;2-i.
Healing of biomaterial implants varies depending on the type and structure of material and the tissue surrounding the implant. In this study we examined structural differences of 30 microm, 60 microm, and 100 microm expanded polytetrafluoroethylene (ePTFE) using scanning electron microscopy, and we also investigated differences in healing for these three different porosity ePTFE grafts implanted within subcutaneous tissue and adipose tissue. Scanning electron microscopic examination of 30 microm, 60 microm, and 100 microm ePTFE revealed structural differences and differences in fiber density within the internodal space. Circular patches (6 mm in diameter) of 30 microm ePTFE were implanted within subcutaneous tissue and epididymal fat pads of male Sprague-Dawley rats. After 5 weeks, the implants were removed and analyzed for fibrous capsule formation, endothelialization, and for activated monocytes and macrophages in association with the material. Histological evaluation revealed dense fibrous capsule formation surrounding only the 30 microm ePTFE subcutaneous implants. From immunohistochemistry data obtained, we generated an Endothelialization Index (measure of neovascularization) and a Monocyte/Macrophage Index (measure of inflammatory response) for each sample. Consistently, 60 microm ePTFE had the greatest Endothelialization Index at both implant sites while 100 microm ePTFE generally had the largest values for the Monocyte/Macrophage Index. These data indicate that both the structure of the material and the site of implant influence the healing characteristics of ePTFE and suggest that activated monocytes and/or macrophages associated with the implant may inhibit endothelialization of ePTFE.
生物材料植入物的愈合情况因材料的类型和结构以及植入物周围的组织而异。在本研究中，我们使用扫描电子显微镜检查了30微米、60微米和100微米的膨体聚四氟乙烯（ePTFE）的结构差异，并且我们还研究了将这三种不同孔隙率的ePTFE移植物植入皮下组织和脂肪组织后的愈合差异。对30微米、60微米和100微米的ePTFE进行扫描电子显微镜检查，揭示了节间空间内的结构差异和纤维密度差异。将直径6毫米的30微米ePTFE圆形贴片植入雄性Sprague-Dawley大鼠的皮下组织和附睾脂肪垫中。5周后，取出植入物并分析纤维囊形成、内皮化以及与材料相关的活化单核细胞和巨噬细胞情况。组织学评估显示，仅在30微米ePTFE皮下植入物周围形成了致密的纤维囊。根据获得的免疫组织化学数据，我们为每个样本生成了一个内皮化指数（新血管形成的度量）和一个单核细胞/巨噬细胞指数（炎症反应的度量）。一致地，60微米ePTFE在两个植入部位均具有最大的内皮化指数，而100微米ePTFE的单核细胞/巨噬细胞指数通常具有最大值。这些数据表明，材料的结构和植入部位均会影响ePTFE的愈合特性，并表明与植入物相关的活化单核细胞和/或巨噬细胞可能会抑制ePTFE的内皮化。
