Campbell C E, von Recum A F
Department of Bioengineering, Clemson University, SC 29634-0905.
J Invest Surg. 1989;2(1):51-74. doi: 10.3109/08941938909016503.
Implants placed in soft tissue evoke a foreign body reaction. Polymeric implants having smooth surfaces, such as silicone rubber implants, develop a nonadherent fibrogranulous tissue capsule which contracts over time and stiffens. Conventional porous implants, such as those made from textiles, usually have pores larger than 20 microns and they become infiltrated with inflammatory tissue. The in vivo cell reaction to polymeric surfaces having pores smaller than 10 microns has not been investigated systematically. In this study the histocompatibility of materials having mean pore diameters from 0.4 to 10 microns was assessed. A material available with several different defined pore sizes Versapor filter material) was tested in vivo to determine relation between pore size and qualitative tissue response. Silicone-coated samples were also tested to determine the dependence of the observed tissue response on the implant surface chemistry. Results showed nonadherent, contracting capsules around implants having pore diameters smaller than 0.5 microns. Implants with pores ranging from 1.4 to 1.9 microns evoked thin, tightly adherent fibrous capsules without inflammatory cells. Porosities of 3.3 microns and larger became infiltrated with inflammatory tissue. Results indicate that the observed tissue response is predominantly dependent on implant surface topography and that variation in implant material may have little effect. It is concluded that a defined surface topography of 1 to 2 microns appears to allow direct fibroblast attachment to the surface independent of its chemical or electrochemical nature. Attached fibroblasts then produce a minimal connective tissue response to the implant and prevent or diminish the presence of inflammatory cells at the implant/tissue interface.
植入软组织中的植入物会引发异物反应。具有光滑表面的聚合物植入物，如硅橡胶植入物，会形成一层非粘连性的纤维颗粒组织包膜，该包膜会随着时间的推移而收缩并变硬。传统的多孔植入物，如由纺织品制成的植入物，其孔隙通常大于20微米，会被炎性组织浸润。对于孔隙小于10微米的聚合物表面，体内细胞反应尚未得到系统研究。在本研究中，评估了平均孔径为0.4至10微米的材料的组织相容性。一种具有几种不同定义孔径的材料（Versapor过滤材料）在体内进行了测试，以确定孔径与定性组织反应之间的关系。还测试了涂有硅酮的样品，以确定观察到的组织反应对植入物表面化学的依赖性。结果显示，孔径小于0.5微米的植入物周围有非粘连性、收缩性的包膜。孔径在1.4至1.9微米之间的植入物引发了薄而紧密粘连的纤维包膜，没有炎性细胞。孔隙率为3.3微米及更大的植入物被炎性组织浸润。结果表明，观察到的组织反应主要取决于植入物的表面形貌，植入材料的变化可能影响很小。得出的结论是，1至2微米的特定表面形貌似乎允许成纤维细胞直接附着于表面，而与其化学或电化学性质无关。附着的成纤维细胞随后对植入物产生最小的结缔组织反应，并防止或减少植入物/组织界面处炎性细胞的存在。
