Electrophoretic Deposition, Microstructure, and Selected Properties of Poly(lactic-co-glycolic) Acid-Based Antibacterial Coatings on Mg Substrate

There is an urgent need to develop biodegradable implants that can degrade once they have fulfilled their function. Commercially pure magnesium (Mg) and its alloys have the potential to surpass traditional orthopedic implants due to their good biocompatibility and mechanical properties, and most critically, biodegradability. The present work focuses on the synthesis and characterization (microstructural, antibacterial, surface, and biological properties) of poly(lactic-co-glycolic) acid (PLGA)/henna (Lawsonia inermis)/Cu-doped mesoporous bioactive glass nanoparticles (Cu-MBGNs) composite coatings deposited via electrophoretic deposition (EPD) on Mg substrates. PLGA/henna/Cu-MBGNs composite coatings were robustly deposited on Mg substrates using EPD, and their adhesive strength, bioactivity, antibacterial activity, corrosion resistance, and biodegradability were thoroughly investigated. Scanning electron microscopy and Fourier transform infrared spectroscopy studies confirmed the uniformity of the coatings’ morphology and the presence of functional groups that were attributable to PLGA, henna, and Cu-MBGNs, respectively. The composites exhibited good hydrophilicity with an average roughness of 2.6 μm, indicating desirable properties for bone forming cell attachment, proliferation, and growth. Crosshatch and bend tests confirmed that the adhesion of the coatings to Mg substrates and their deformability were adequate. Electrochemical Tafel polarization tests revealed that the composite coating adjusted the degradation rate of Mg substrate in a human physiological environment. Incorporating henna into PLGA/Cu-MBGNs composite coatings resulted in antibacterial activity against Escherichia coli and Staphylococcus aureus. The coatings stimulated the proliferation and growth of osteosarcoma MG-63 cells during the initial incubation period of 48 h (determined by the WST-8 assay).当前迫切需要开发出在完成既定功能后可自行降解的生物可降解植入物。商业纯镁（Mg）及其合金凭借优异的生物相容性、力学性能，以及最为关键的生物可降解性，有望超越传统骨科植入物。本研究聚焦于以镁基底为载体，通过电泳沉积法（EPD）制备的聚乳酸-羟基乙酸共聚物（PLGA）/散沫花（Lawsonia inermis）/铜掺杂介孔生物活性玻璃纳米颗粒（Cu-MBGNs）复合涂层的合成与表征，表征维度涵盖微观结构、抗菌性能、表面性能与生物学性能。研究人员通过电泳沉积法成功在镁基底上牢固制备了PLGA/散沫花/Cu-MBGNs复合涂层，并对其粘接强度、生物活性、抗菌活性、耐腐蚀性能与生物可降解性开展了全面的系统表征。扫描电子显微镜与傅里叶变换红外光谱分析证实，该涂层形貌均匀，且分别存在对应于PLGA、散沫花与Cu-MBGNs的特征官能团。该复合材料表现出良好的亲水性，平均粗糙度为2.6 μm，这一特性可为成骨细胞的黏附、增殖与生长提供理想的环境。十字划格试验与弯折试验证实，该涂层与镁基底之间的粘接性能优异，且涂层自身的变形能力满足应用要求。电化学塔菲尔极化测试结果表明，该复合涂层可在人体生理环境中调控镁基底的降解速率。将散沫花引入PLGA/Cu-MBGNs复合涂层后，该涂层对大肠埃希菌与金黄色葡萄球菌均表现出显著的抗菌活性。通过WST-8法检测发现，在初始培养48小时内，该涂层可有效促进骨肉瘤MG-63细胞的增殖与生长。