College of Lab Medicine, Hebei North University, Key Laboratory of Biomedical Materials of Zhangjiakou, Zhangjiakou 075000, China.
School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, China.
Mater Sci Eng C Mater Biol Appl. 2021 Oct;129:112387. doi: 10.1016/j.msec.2021.112387. Epub 2021 Aug 21.
Zinc-based biometal is expected to become a new generation of biodegradable implants. Due to its antibacterial and biocompatibility in vivo, zinc metals is recently considered to be the most promising biodegradable metal, However, cytotoxicity is the thorny problem that currently restrict its application, due to the excessive Zn ions released during degradation. In order to solve these problems, dopamine modified strontium-doped hydroxyapatite coating (SrHA/PDA) was fabricated on alkali-treated pure zinc to improve its corrosion rate and cytocompatibility by electrodeposition for the first time. The obtained coating showed a dense structure and high crystallinity, which was attributed to the attraction of Ca ions by polydopamine. The results showed that the SrHA/PDA coating delayedthe degradation rate of zinc metal, which reduced the release of Zn, thereby reducing its cytotoxicity. Additionally, electrochemical tests showed that SrHA/PDA coating can reduce the corrosion rate of pure zinc. In vitro cell viability showed that even at high Zn concentrations (3.11 mg/L), preosteoblasts (MC3T3-E1) cells proliferated at a high rate on SrHA/PDA, thus confirming that Sr counteracted the cytotoxic effects of Zn and promoted cell differentiation. Moreover, the SrHA/PDA coating still maintained excellent antibacterial effects against pathogenic bacterial strains (Escherichia coli and Staphylococcus aureus). Mild pH changes had no significant effect on the viability of cells and bacterias. Collectively, the present study elucidated that by coating SrHA/PDA/Zn(OH) on Zn, a controllable corrosion rate, original antibacterial properties and better cell compatibility can be achieved. This provided a new strategy for the surface modification of biodegradable Zn.
基于锌的生物金属有望成为新一代可生物降解的植入物。由于其在体内的抗菌和生物相容性，锌金属最近被认为是最有前途的可生物降解金属，然而，细胞毒性是目前限制其应用的棘手问题，这是由于降解过程中释放出过多的 Zn 离子。为了解决这些问题，首次通过电沉积在经过碱处理的纯锌上制备了多巴胺改性锶掺杂羟基磷灰石涂层（SrHA/PDA），以提高其腐蚀速率和细胞相容性。所得涂层具有致密的结构和高结晶度，这归因于聚多巴胺对 Ca 离子的吸引力。结果表明，SrHA/PDA 涂层可延缓锌金属的降解速率，从而减少 Zn 的释放，从而降低其细胞毒性。此外，电化学测试表明 SrHA/PDA 涂层可以降低纯锌的腐蚀速率。体外细胞活力表明，即使在高 Zn 浓度（3.11 mg/L）下，成骨前体细胞（MC3T3-E1）在 SrHA/PDA 上仍能高速增殖，从而证实 Sr 拮抗了 Zn 的细胞毒性作用并促进了细胞分化。此外，SrHA/PDA 涂层对病原菌（大肠杆菌和金黄色葡萄球菌）仍保持优异的抗菌效果。温和的 pH 值变化对细胞和细菌的活力没有显著影响。总之，本研究阐明了通过在 Zn 上涂覆 SrHA/PDA/Zn(OH)，可以实现可控制的腐蚀速率、原始的抗菌性能和更好的细胞相容性。这为可生物降解 Zn 的表面改性提供了一种新策略。
