Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China.
School of Materials Science and Engineering, University of Science and Technology of China, 96 Jinzhai Road, Hefei, China 230026.
ACS Biomater Sci Eng. 2020 Mar 9;6(3):1355-1366. doi: 10.1021/acsbiomaterials.9b01396. Epub 2020 Feb 19.
Implant-related infections are a major concern in total joint prostheses, occurring up to 3% in operations. In this work, 5% Zn was added in HA to offset bacterial activity and 5% Sr was also incorporated as a binary dopant to reduce the cytotoxic effect of Zn. The nanosized HA powder was synthesized by the hydrothermal method and then heat-treated at 600 °C for 4 h. The heat-treated powder was plasma-sprayed on a titanium alloy Ti-6Al-4V substrate. The addition of the dopant did not significantly influence the physical and mechanical properties of the coating. However, the cytocompatibility, antimicrobial, and contact-angle properties statistically enhanced. Moreover, the (Sr,Zn)-HA coating was post-heat treated at 500 and 600 °C for 3 h. X-ray diffraction confirmed that after heat treatment phase purity and crystallinity increased and residual stress decreased. Mechanical stability was evaluated by adhesive bond strength, and the results showed that after heat-treatment bonding strength increased from 26.81 ± 2.93 to 29.84 ± 3.62 and 34.66 ± 2.57 MPa, at 500 and 600 °C, respectively. Similar to the mechanical property, antibacterial activities and biological functions are also significantly improved. More interestingly, it was also observed that the Zn ions released from the coating depend on Ca, P, and Sr ions while Ca, P, and Sr ions relied on heat treatment temperatures. However, (Sr,Zn)-HA coating at 600 °C demonstrates cytotoxic effects on MC3T3-E1 cells, characterized by poor cellular morphology on the coating surface and ultimately, cell death. The doping of Sr with Zn, therefore, can offset the cytotoxic effects and enhanced biological performance. All of the outcomes of this study signify that (Sr,Zn)-HA coating heat-treated at 500 °C showed not only excellent mechanical and biological performance but also enhanced the antibacterial properties.
植入物相关感染是全关节假体的主要关注点，在手术中发生率高达 3%。在这项工作中，在 HA 中添加了 5%的 Zn 以抵消细菌活性，并且还掺入了 5%的 Sr 作为二元掺杂剂以降低 Zn 的细胞毒性。纳米 HA 粉末通过水热法合成，然后在 600°C 下热处理 4 小时。将热处理后的粉末通过等离子喷涂在钛合金 Ti-6Al-4V 基底上。掺杂剂的添加对涂层的物理和机械性能没有显著影响。然而，细胞相容性、抗菌性和接触角性能都得到了统计学上的提高。此外，(Sr,Zn)-HA 涂层在 500 和 600°C 下分别进行了 3 小时的后热处理。X 射线衍射证实，热处理后相纯度和结晶度增加，残余应力降低。通过结合强度评估机械稳定性，结果表明，热处理后结合强度从 26.81±2.93MPa 增加到 29.84±3.62MPa 和 34.66±2.57MPa，分别在 500°C 和 600°C。类似的机械性能，抗菌活性和生物功能也得到了显著提高。更有趣的是，还观察到涂层中释放的 Zn 离子取决于 Ca、P 和 Sr 离子，而 Ca、P 和 Sr 离子则依赖于热处理温度。然而，(Sr,Zn)-HA 涂层在 600°C 下对 MC3T3-E1 细胞表现出细胞毒性作用，其特征是涂层表面的细胞形态差，最终导致细胞死亡。因此，Zn 与 Sr 的掺杂可以抵消细胞毒性作用并提高生物性能。本研究的所有结果表明，在 500°C 下热处理的(Sr,Zn)-HA 涂层不仅表现出优异的机械和生物学性能，而且还增强了抗菌性能。
