Osak Patrycja, Maszybrocka Joanna, Kubisztal Julian, Ratajczak Patryk, Łosiewicz Bożena
Faculty of Science and Technology, Institute of Materials Engineering, University of Silesia in Katowice, 75 Pułku Piechoty 1A, 41-500 Chorzów, Poland.
J Funct Biomater. 2021 Feb 7;12(1):12. doi: 10.3390/jfb12010012.
Calcium phosphate coatings are able to improve the osseointegration process due to their chemical composition, which is similar to that of bone tissues. In this work, to increase the long-term corrosion resistance and to improve the osseointegration process of commercially pure titanium Grade 4 (CpTi G4), biomimetic amorphous calcium phosphate (ACP) coatings were electrodeposited for the first time from an acetate bath with a pH level of 7.0 and a Ca:P ratio of 1.67. ACP coatings were obtained on CpTi G4 substrate subjected to sandblasting and autoclaving using electrochemically assisted deposition at a potential of -3 V relative to the open circuit potential for 30 min at room temperature. SEM, EDS, 2D roughness profiles, amplitude-sensitive eddy current method, and Kelvin scanning probe were used for the surface characterization of the biomaterial under study. In vitro corrosion resistance tests were conducted for 21 days in artificial saliva using open circuit potential, polarization curves, and electrochemical impedance spectroscopy measurements. The passive-transpassive behavior was revealed for the obtained ACP coatings. The long-term corrosion resistance test showed a deterioration of the protective properties for CpTi G4 uncoated and coated with ACP with immersion time. The mechanism and kinetics of the pitting corrosion on the CpTi G4|TiO|ACP coating system are discussed in detail.
磷酸钙涂层由于其化学成分与骨组织相似，能够改善骨整合过程。在本研究中，为了提高商业纯4级钛（CpTi G4）的长期耐腐蚀性并改善其骨整合过程，首次在pH值为7.0、钙磷比为1.67的醋酸盐浴中通过电化学辅助沉积电沉积了仿生无定形磷酸钙（ACP）涂层。在经过喷砂和高压灭菌处理的CpTi G4基体上，采用相对于开路电位为-3 V的电位在室温下进行30分钟的电化学辅助沉积，从而获得ACP涂层。使用扫描电子显微镜（SEM）、能谱仪（EDS）、二维粗糙度轮廓仪、振幅敏感涡流法和开尔文扫描探针，对所研究的生物材料进行表面表征。使用开路电位、极化曲线和电化学阻抗谱测量方法，在人工唾液中进行了21天的体外耐腐蚀性测试。所获得的ACP涂层表现出钝化-过钝化行为。长期耐腐蚀性测试表明，未涂层的CpTi G4以及涂覆有ACP的CpTi G4的防护性能会随着浸泡时间而变差。详细讨论了CpTi G4|TiO|ACP涂层体系点蚀的机理和动力学。
