Fraunhofer Center for Coatings and Laser Applications, East Lansing, Michigan 48823, USA.
J Biomed Mater Res A. 2010 Nov;95(2):388-400. doi: 10.1002/jbm.a.32851.
Diamond-like carbon (DLC) films are favored for wear components because of diamond-like hardness, low friction, low wear, and high corrosion resistance (Schultz et al., Mat-wiss u Werkstofftech 2004;35:924-928; Lappalainen et al., J Biomed Mater Res B Appl Biomater 2003;66B:410-413; Tiainen, Diam Relat Mater 2001;10:153-160). Several studies have demonstrated their inertness, nontoxicity, and the biocompatibility, which has led to interest among manufacturers of surgical implants (Allen et al., J Biomed Mater Res B Appl Biomater 2001;58:319-328; Uzumaki et al., Diam Relat Mater 2006;15:982-988; Hauert, Diam Relat Mater 2003;12:583-589; Grill, Diam Relat Mater 2003;12:166-170). In this study, hydrogen-free amorphous, tetrahedrally bonded DLC films (ta-C) were deposited at low temperatures by physical vapor deposition on medical grade Co28Cr6Mo steel and the titanium alloy Ti6Al4V (Scheibe et al., Surf Coat Tech 1996;85:209-214). The mechanical performance of the ta-C was characterized by measuring its surface roughness, contact angle, adhesion, and wear behavior, whereas the biocompatibility was assessed by osteoblast (OB) attachment and cell viability via Live/Dead assay. There was no statistical difference found in the wettability as measured by contact angle measurements for the ta-C coated and the uncoated samples of either Co28Cr6Mo or Ti6Al4V. Rockwell C indentation and dynamic scratch testing on 2-10 μm thick ta-C films on Co28Cr6Mo substrates showed excellent adhesion with HF1 grade and up to 48 N for the critical load L(C2) during scratch testing. The ta-C coating reduced the wear from 3.5 × 10(-5) mm(3)/Nm for an uncoated control sample (uncoated Co28Cr6Mo against uncoated stainless steel) to 1.1 × 10(-7) mm(3)/Nm (coated Co28Cr6Mo against uncoated stainless steel) in reciprocating pin-on-disk testing. The lowest wear factor of 3.9 × 10(-10) mm(3)/Nm was measured using a ta-C coated steel ball running against a ta-C coated and polished Co28Cr6Mo disk. Student's t-test found that the ta-C coating had no statistically significant (p < 0.05) effect on OB attachment, when compared with the uncoated control samples. There was no significant difference (p < 0.05) in the Live/Dead assay results in cell death between the ta-C coated Co28Cr6Mo and Ti6Al4V samples and the uncoated controls. Therefore, these ta-C coatings show improved wear and corrosion (Dorner-Reisel et al., Diam Relat Mater 2003;11:823-827; Affato et al., J Biomed Mater Res B Appl Biomater 2000;53:221-226; Dorner-Reisel et al., Surf Coat Tech 2004;177-178:830-837; Kim et al., Diam Relat Mater 2004;14:35-41) performance and excellent in vitro cyto-compatibility, when compared with currently used uncoated Co28Cr6Mo and Ti6Al4V implant materials.
类金刚石碳 (DLC) 薄膜因其类金刚石硬度、低摩擦、低磨损和高耐腐蚀性而受到耐磨部件的青睐 (Schultz 等人，Mat-wiss u Werkstofftech 2004;35:924-928; Lappalainen 等人，J Biomed Mater Res B Appl Biomater 2003;66B:410-413; Tiainen，Diam Relat Mater 2001;10:153-160)。多项研究表明，DLC 薄膜具有惰性、无毒和生物相容性，这引起了外科植入物制造商的兴趣 (Allen 等人，J Biomed Mater Res B Appl Biomater 2001;58:319-328; Uzumaki 等人，Diam Relat Mater 2006;15:982-988; Hauert，Diam Relat Mater 2003;12:583-589; Grill，Diam Relat Mater 2003;12:166-170)。在这项研究中，通过物理气相沉积在医用级 Co28Cr6Mo 钢和钛合金 Ti6Al4V 上沉积了无氢非晶态、四面体键合的 DLC 薄膜 (ta-C) (Scheibe 等人，Surf Coat Tech 1996;85:209-214)。通过测量 ta-C 的表面粗糙度、接触角、附着力和磨损行为来表征其机械性能，通过活/死测定评估其生物相容性。对于 Co28Cr6Mo 或 Ti6Al4V 的 ta-C 涂层和未涂层样品，接触角测量的润湿性没有统计学差异。在 Co28Cr6Mo 基底上的 2-10 μm 厚的 ta-C 薄膜上进行的洛氏 C 压痕和动态划痕测试表明，HF1 级的附着力优异，在划痕测试过程中临界载荷 L(C2)可达 48 N。ta-C 涂层使磨损从未涂层对照样品（未涂层 Co28Cr6Mo 对未涂层不锈钢）的 3.5×10(-5)mm(3)/Nm 降低到 1.1×10(-7)mm(3)/Nm（涂覆 Co28Cr6Mo 对未涂层不锈钢）在往复销盘测试中。使用涂覆 ta-C 的钢球在涂覆 ta-C 的和抛光的 Co28Cr6Mo 盘上运行时，测量到最低的磨损系数为 3.9×10(-10)mm(3)/Nm。学生 t 检验发现，与未涂层对照样品相比，ta-C 涂层对 OB 附着没有统计学意义（p<0.05）的影响。ta-C 涂层 Co28Cr6Mo 和 Ti6Al4V 样品与未涂层对照之间的活/死测定结果在细胞死亡方面没有显著差异（p<0.05）。因此，与目前使用的未涂层 Co28Cr6Mo 和 Ti6Al4V 植入材料相比，这些 ta-C 涂层具有改善的耐磨性和耐腐蚀性（Dorner-Reisel 等人，Diam Relat Mater 2003;11:823-827;Affato 等人，J Biomed Mater Res B Appl Biomater 2000;53:221-226;Dorner-Reisel 等人，Surf Coat Tech 2004;177-178:830-837;Kim 等人，Diam Relat Mater 2004;14:35-41）性能和优异的体外细胞相容性。
