Hou Xiaoning, Qin Haifeng, Gao Hongyu, Mankoci Steven, Zhang Ruixia, Zhou Xianfeng, Ren Zhencheng, Doll Gary L, Martini Ashlie, Sahai Nita, Dong Yalin, Ye Chang
Department of Mechanical Engineering, University of Akron, Akron, OH 44325, USA.
Timken Engineered Surfaces Laboratories, University of Akron, Akron, OH 44325, USA.
Mater Sci Eng C Mater Biol Appl. 2017 Sep 1;78:1061-1071. doi: 10.1016/j.msec.2017.04.128. Epub 2017 Apr 23.
Magnesium alloys have tremendous potential for biomedical applications due to their good biocompatibility, osteoconductivity, and degradability, but can be limited by their poor mechanical properties and fast corrosion in the physiological environment. In this study, ultrasonic nanocrystal surface modification (UNSM), a recently developed surface processing technique that utilizes ultrasonic impacts to induce plastic strain on metal surfaces, was applied to an AZ31B magnesium (Mg) alloy. The mechanical properties, corrosion resistance, and biocompatibility of the alloy after UNSM treatment were studied systematically. Significant improvement in hardness, yield stress and wear resistance was achieved after the UNSM treatment. In addition, the corrosion behavior of UNSM-treated AZ31B was not compromised compared with the untreated samples, as demonstrated by the weight loss and released element concentrations of Mg and Al after immersion in alpha-minimum essential medium (α-MEM) for 24h. The in vitro biocompatibility of the AZ31B Mg alloys toward adipose-derived stem cells (ADSCs) before and after UNSM processing was also evaluated using a cell culture study. Comparable cell attachments were achieved between the two groups. These studies showed that UNSM could significantly improve the mechanical properties of Mg alloys without compromising their corrosion rate and biocompatibility in vitro. These findings suggest that UNSM is a promising method to treat biodegradable Mg alloys for orthopaedic applications.
镁合金因其良好的生物相容性、骨传导性和可降解性，在生物医学应用方面具有巨大潜力，但可能会受到其较差的力学性能和在生理环境中快速腐蚀的限制。在本研究中，超声纳米晶表面改性（UNSM），一种最近开发的利用超声冲击在金属表面诱导塑性应变的表面处理技术，被应用于AZ31B镁（Mg）合金。系统研究了UNSM处理后该合金的力学性能、耐腐蚀性和生物相容性。UNSM处理后，合金的硬度、屈服应力和耐磨性有显著提高。此外，浸泡在α-最低基本培养基（α-MEM）中24小时后，经UNSM处理的AZ31B的失重以及Mg和Al释放元素浓度表明，其腐蚀行为与未处理样品相比并未受到影响。还通过细胞培养研究评估了UNSM处理前后AZ31B镁合金对脂肪干细胞（ADSCs）的体外生物相容性。两组之间实现了相当的细胞附着。这些研究表明，UNSM可以显著改善镁合金的力学性能，而不影响其体外腐蚀速率和生物相容性。这些发现表明，UNSM是一种用于治疗可降解镁合金以用于骨科应用的有前途的方法。
