Institute of Stomatology, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou 325027, China; School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China.
Institute of Stomatology, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou 325027, China.
Acta Biomater. 2023 Oct 1;169:641-660. doi: 10.1016/j.actbio.2023.07.061. Epub 2023 Aug 2.
Zinc (Zn) and its alloys are used in bone-fixation devices as biodegradable bone-implant materials due to their good biosafety, biological function, biodegradability, and formability. Unfortunately, the clinical application of pure Zn is hindered by its insufficient mechanical properties and slow degradation rate. In this study, a Zn-5 wt.% lanthanum (Zn-5La) alloy with enhanced mechanical properties, suitable degradation rate, and cytocompatibility was developed through La alloying and hot extrusion. The hot-extruded (HE) Zn-5La alloy showed ultimate tensile strength of 286.3 MPa, tensile yield strength of 139.7 MPa, elongation of 35.7%, compressive yield strength of 262.7 MPa, and microhardness of 109.7 HV. The corrosion resistance of the HE Zn-5La in Hanks' and Dulbecco's modified Eagle medium (DMEM) solutions gradually increased with prolonged immersion time. Further, the HE Zn-5La exhibited an electrochemical corrosion rate of 36.7 μm/y in Hanks' solution and 11.4 μm/y in DMEM solution, and a degradation rate of 49.5 μm/y in Hanks' solution and 30.3 μm/y in DMEM solution, after 30 d of immersion. The corrosion resistance of both HE Zn and Zn-5La in DMEM solution was higher than in Hanks' solution. The 25% concentration extract of the HE Zn-5La showed a cell viability of 106.5%, indicating no cytotoxicity toward MG-63 cells. We recommend the HE Zn-5La alloy as a promising candidate material for biodegradable bone-implant applications. STATEMENT OF SIGNIFICANCE: This work reports the mechanical properties, corrosion and degradation behaviors, in vitro cytocompatibility and antibacterial ability of biodegradable Zn-5La alloy for bone-implant applications. Our findings demonstrate that the hot-extruded (HE) Zn-5La alloy showed an ultimate tensile strength of 286.3 MPa, a yield strength of 139.7 MPa, an elongation of 35.7%, compressive yield strength of 262.7 MPa, and microhardness of 109.7 HV. HE Zn-5La exhibited appropriate degradation rates in Hanks' and DMEM solutions. Furthermore, the HE Zn-5La alloy showed good cytocompatibility toward MG-63 and MC3T3-E1 cells and greater antibacterial ability against S. aureus.
锌（Zn）及其合金因其良好的生物安全性、生物功能、生物降解性和可成形性，被用作骨固定装置中的可生物降解的骨植入材料。不幸的是，由于纯锌机械性能不足和降解速度缓慢，其临床应用受到限制。在这项研究中，通过镧合金化和热挤压，开发了一种具有增强的机械性能、合适的降解率和细胞相容性的 Zn-5wt.%镧（Zn-5La）合金。热挤压（HE）Zn-5La 合金的拉伸强度为 286.3MPa，屈服强度为 139.7MPa，伸长率为 35.7%，压缩屈服强度为 262.7MPa，显微硬度为 109.7HV。在 Hank's 和 Dulbecco 改良 Eagle 培养基（DMEM）溶液中，HE Zn-5La 的耐腐蚀性随着浸泡时间的延长而逐渐增加。此外，HE Zn-5La 在 Hank's 溶液中的电化学腐蚀速率为 36.7μm/y，在 DMEM 溶液中的腐蚀速率为 11.4μm/y，在 Hank's 溶液中的降解速率为 49.5μm/y，在 DMEM 溶液中的降解速率为 30.3μm/y，浸泡 30 天后。HE Zn 和 Zn-5La 在 DMEM 溶液中的耐腐蚀性均高于 Hank's 溶液。HE Zn-5La 的 25%浓度浸提液对 MG-63 细胞的细胞活力为 106.5%，表明对 MG-63 细胞无细胞毒性。我们推荐 HE Zn-5La 合金作为一种有前途的可生物降解骨植入应用候选材料。
本工作报告了可生物降解 Zn-5La 合金用于骨植入应用的机械性能、腐蚀和降解行为、体外细胞相容性和抗菌能力。我们的研究结果表明，热挤压（HE）Zn-5La 合金的拉伸强度为 286.3MPa，屈服强度为 139.7MPa，伸长率为 35.7%，压缩屈服强度为 262.7MPa，显微硬度为 109.7HV。HE Zn-5La 在 Hank's 和 DMEM 溶液中的降解速率适中。此外，HE Zn-5La 合金对 MG-63 和 MC3T3-E1 细胞具有良好的细胞相容性，对金黄色葡萄球菌具有更强的抗菌能力。
