Department of Oral Implantology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
Xiangya Hospital Stomatological Hospital, Central South University, Changsha, Hunan 410000, China; Department of Dentistry-Biomaterials, Radboud University Medical Center, Philips van Leydenlaan 25, 6525 EX Nijmegen, the Netherlands.
Mater Sci Eng C Mater Biol Appl. 2021 Dec;131:112491. doi: 10.1016/j.msec.2021.112491. Epub 2021 Oct 14.
Calcium phosphate coating is an attractive surface modification strategy for magnesium alloys, since it can increase their corrosion resistance and endow them with osteogenic function simultaneously. Herein, a calcium metaphosphate (CMP) coating was fabricated on magnesium alloy by using sol-gel approach assisted with micro-arc oxidation pre-treatment. Scanning electron microscopy showed that the micro-pores and cracks in micro-arc oxidation inner layer generated during the pre-treatment process were sealed by the grainy sol-gel outer layer. Energy dispersive spectrometry and X-ray diffraction results demonstrated the identity of the coating as CMP. The cross-cut test showed that the adhesion of CMP coating was strong. Applying bare magnesium alloy substrate as a control, the CMP coating surface was rougher and more hydrophilic. The potentiodynamic polarization test demonstrated that the corrosion resistance was significantly improved by using CMP coating. Hydrogen evolution in immersion test further confirmed that the degradation rate was decelerated within 14 days. Moreover, CMP coating facilitated the adhesion speed, spreading area, and focal adhesion formation of bone marrow stem cells. The number of cells in the active proliferating state and proliferated cells present on the CMP coating also increased. Additionally, CMP coating upregulated alkaline phosphatase activity and osteogenic gene expression in cells. In summary, the micro-arc oxidation assisted sol-gel CMP coatings increased the corrosion resistance and promoted the interfacial cell behavior for magnesium alloy implants, which might inform the further development of surface modifications on magnesium alloys for bone related applications.
磷酸钙涂层是一种有吸引力的镁合金表面改性策略，因为它可以同时提高其耐腐蚀性并赋予其成骨功能。在此，通过溶胶-凝胶法辅助微弧氧化预处理在镁合金上制备了磷酸钙镁（CMP）涂层。扫描电子显微镜显示，预处理过程中微弧氧化内层产生的微孔和裂纹被颗粒状溶胶-凝胶外层密封。能谱和 X 射线衍射结果表明涂层的成分是 CMP。十字切割试验表明 CMP 涂层的附着力很强。以未涂覆的镁合金基底作为对照，CMP 涂层表面更粗糙，亲水性更好。动电位极化试验表明 CMP 涂层显著提高了耐腐蚀性。浸泡试验中的氢析出进一步证实降解速率在 14 天内减慢。此外，CMP 涂层促进了骨髓干细胞的黏附速度、扩展面积和焦点黏附的形成。处于活跃增殖状态的细胞数量和增殖细胞在 CMP 涂层上也增加了。此外，CMP 涂层上调了细胞中的碱性磷酸酶活性和成骨基因表达。综上所述，微弧氧化辅助溶胶-凝胶 CMP 涂层提高了镁合金植入物的耐腐蚀性，并促进了界面细胞行为，这可能为用于骨骼相关应用的镁合金表面改性的进一步发展提供信息。
