Department of Mechanical Engineering and Engineering Science, The University of North Carolina at Charlotte, Charlotte, North Carolina, USA.
J Biomed Mater Res B Appl Biomater. 2011 Nov;99(2):369-79. doi: 10.1002/jbm.b.31908. Epub 2011 Sep 21.
Bioactive silica-calcium phosphate nanocomposite (SCPC) has been coated on Ti-6Al-4V implant employing an electrophoretic deposition (EPD) technique. The effects of composition and pH of the suspending medium on the zeta potential of three different SCPC formulations; SCPC25, SCPC50 and SCPC75 were analyzed. The average zeta potential of SCPC50 in pure ethanol was more negative than that of SCPC25 or SCPC75; however, the difference was not statistically significant. Discs of Ti-6Al-4V were passivated, coated with SCPC50 (200 nm-10 μm) and thermally treated at 600-800°C to produce a coating thickness in the range of 43.1 ± 5.7 to 30.1 ± 4.6 μm. After treatment at 600, 700, and 800°C, the adhesion strength at the SCPC50/Ti-6Al-4V interface was 42.6 ± 3.6, 44.7 ± 8.7, and 47.2 ± 4.3 MPa, respectively. SEM-EDX analyses of SCPC50-coated Ti-6Al-4V preimmersed in PBS for 7 days showed the formation of a Ca-deficient hydroxyapatite surface layer. ICP-OES analyses of the immersing solution (n = 6) showed an increase in the ionic concentration of Si from 3.3 ± 0.9 to 5.0 ± 1.2 ppm between days 1 and 4; after which no significant change in the Si concentration was measured. Bone marrow mesenchymal stem cells attached to the SCPC50-coated implants expressed significantly higher (p < 0.05) alkaline phosphatase activity (82.4 ± 25.6 nmoles p-NP/mg protein/min) than that expressed by cells attached to HA-coated or uncoated implants. Results of the study suggest that bioactive SCPC50 can efficiently be coated on Ti-6Al-4V using EPD. The SCPC50 coating has the potential to enhance bone integration with the orthopedic implant.
采用电泳沉积（EPD）技术在 Ti-6Al-4V 植入物上涂覆了生物活性硅钙磷酸纳米复合材料（SCPC）。分析了三种不同 SCPC 配方（SCPC25、SCPC50 和 SCPC75）的悬浮液组成和 pH 对 Zeta 电位的影响。在纯乙醇中，SCPC50 的平均 Zeta 电位比 SCPC25 或 SCPC75 更负；然而，差异没有统计学意义。Ti-6Al-4V 圆盘经过钝化处理，涂覆 SCPC50（200nm-10μm）并在 600-800°C 下进行热处理，以产生 43.1±5.7 至 30.1±4.6μm 的涂层厚度。在 600、700 和 800°C 处理后，SCPC50/Ti-6Al-4V 界面的结合强度分别为 42.6±3.6、44.7±8.7 和 47.2±4.3MPa。在 PBS 中浸泡 7 天后，对涂覆有 SCPC50 的 Ti-6Al-4V 进行 SEM-EDX 分析，显示形成了缺钙羟基磷灰石表面层。ICP-OES 分析（n=6）表明，在第 1 天到第 4 天之间，浸出溶液中 Si 的离子浓度从 3.3±0.9ppm 增加到 5.0±1.2ppm；之后，Si 浓度没有明显变化。附着在 SCPC50 涂层植入物上的骨髓间充质干细胞表达的碱性磷酸酶活性（82.4±25.6nmoles p-NP/mg 蛋白/分钟）明显高于附着在 HA 涂层或未涂层植入物上的细胞（p<0.05）。研究结果表明，生物活性 SCPC50 可以通过 EPD 有效地涂覆在 Ti-6Al-4V 上。SCPC50 涂层具有增强与骨科植入物骨整合的潜力。
