Lincks J, Boyan B D, Blanchard C R, Lohmann C H, Liu Y, Cochran D L, Dean D D, Schwartz Z
Wilford Hall Medical Center, Lackland AFB, Department of Periodontics, University of Texas Health Science Centre, San Antonio, USA.
Biomaterials. 1998 Dec;19(23):2219-32. doi: 10.1016/s0142-9612(98)00144-6.
The success of an implant is determined by its integration into the tissue surrounding the biomaterial. Surface roughness and composition are considered to influence the properties of adherent cells. The aim of this study was to determine the effect of chemical composition and surface roughness of commercially pure titanium (Ti) and Ti-6A1-4V alloy (Ti-A) on MG63 osteoblast-like cells. Unalloyed and alloyed Ti disks were machined and either fine-polished or wet-ground, resulting in smooth (S) and rough (R) finishes, respectively. Standard tissue culture plastic was used as a control. Surface topography and profile were evaluated by cold field emission scanning electron microscopy and profilometry, while chemical composition was determined using Auger electron spectroscopy and Fourier transform infrared spectroscopy. The effect on the cells was evaluated 24 h postconfluence by measuring cell number, [3H]-thymidine incorporation into DNA, cell and cell layer alkaline phosphatase specific activity (ALPase), osteocalcin and collagen production, [35S]-sulfate incorporation into proteoglycan, and prostaglandin E2 (PGE2) and transforming growth factor-beta (TGF-beta) production. When compared to plastic, the number of cells was reduced on the pure Ti surfaces, while it was equivalent on the Ti-A surfaces; [3H]-thymidine incorporation was reduced on all surfaces. The stimulatory effect of surface roughness on ALPase in isolated cells and the cell layer was more pronounced on the rougher surfaces, with enzyme activity on Ti-R being greater than on Ti-A-R. Osteocalcin production was increased only on the Ti-R surface. Collagen production was decreased on Ti surfaces except Ti-R; [35S]-sulfate incorporation was reduced on all surfaces. Surface roughness affected local factor production (TGF-beta, PGE2). The stimulatory effect of the rougher surfaces on PGE2 and TGF-beta was greater on Ti than Ti-A. In summary, cell proliferation, differentiation, protein synthesis and local factor production were affected by surface roughness and composition. Enhanced differentiation of cells grown on rough vs. smooth surfaces for both Ti and Ti-A surfaces was indicated by decreased proliferation and increased ALPase and osteocalcin production. Local factor production was also enhanced on rough surfaces, supporting the contention that these cells are more differentiated. Surface composition also played a role in cell differentiation, since cells cultured on Ti-R surfaces produced more ALPase than those cultured on Ti-A-R. While it is still unknown which material properties induce which cellular responses, this study suggests that surface roughness and composition may play a major role and that the best design for an orthopaedic implant is a pure titanium surface with a rough microtopography.
植入物的成功取决于其与生物材料周围组织的整合情况。表面粗糙度和成分被认为会影响贴壁细胞的特性。本研究的目的是确定商业纯钛（Ti）和Ti-6Al-4V合金（Ti-A）的化学成分和表面粗糙度对MG63成骨样细胞的影响。对未合金化和合金化的钛盘进行加工，分别进行精细抛光或湿磨，从而得到光滑（S）和粗糙（R）的表面。使用标准组织培养塑料作为对照。通过冷场发射扫描电子显微镜和轮廓仪评估表面形貌和轮廓，同时使用俄歇电子能谱和傅里叶变换红外光谱确定化学成分。在汇合后24小时，通过测量细胞数量、[3H] - 胸苷掺入DNA的量、细胞和细胞层碱性磷酸酶比活性（ALPase）、骨钙素和胶原蛋白的产生、[35S] - 硫酸盐掺入蛋白聚糖的量以及前列腺素E2（PGE2）和转化生长因子-β（TGF-β）的产生来评估对细胞的影响。与塑料相比，纯钛表面的细胞数量减少，而Ti-A表面的细胞数量相当；所有表面上[3H] - 胸苷掺入量均减少。表面粗糙度对分离细胞和细胞层中ALPase的刺激作用在较粗糙表面上更为明显，Ti-R上的酶活性大于Ti-A-R。仅在Ti-R表面骨钙素产生增加。除Ti-R外，Ti表面的胶原蛋白产生减少；所有表面上[35S] - 硫酸盐掺入量均减少。表面粗糙度影响局部因子的产生（TGF-β、PGE2）。较粗糙表面对PGE2和TGF-β的刺激作用在Ti上比在Ti-A上更大。总之，细胞增殖、分化、蛋白质合成和局部因子产生受表面粗糙度和成分的影响。Ti和Ti-A表面上生长在粗糙表面与光滑表面上的细胞，其增殖减少以及ALPase和骨钙素产生增加，表明细胞分化增强。粗糙表面上局部因子产生也增强，支持了这些细胞更具分化性的观点。表面成分在细胞分化中也起作用，因为在Ti-R表面培养的细胞比在Ti-A-R表面培养的细胞产生更多的ALPase。虽然仍不清楚哪些材料特性引发哪些细胞反应，但本研究表明表面粗糙度和成分可能起主要作用，并且骨科植入物的最佳设计是具有粗糙微观形貌的纯钛表面。
