Department of Metallurgical and Materials Engineering, Muğla Sıtkı Koçman University, 48000 Muğla, Türkiye.
Stem Cells and Medical Genetics Units, Tecnologica Research Institute and Marrelli Health, 88900 Crotone, Italy.
J Mater Chem B. 2024 Nov 13;12(44):11477-11490. doi: 10.1039/d4tb01214c.
: Magnesium alloys degrade rapidly in salt solutions, which limits their use without passivating treatments. AZ31 alloy is particularly promising for implant applications owing to its biodegradability and mechanical properties, necessitating effective corrosion-resistant coatings. : In this study, a self-passivating reactive coating was designed and evaluated for AZ31 magnesium alloy plates using β-tricalcium phosphate (TCP) to enhance corrosion resistance and biocompatibility. : Solutions of TCP, trisodium citrate, magnesium nitrate, hydroxyethyl cellulose (HEC), and sodium chloride were used to dip-coat AZ31 plates. The coated samples were immersed in 3.5 wt% NaCl solution. Phase evolution was analysed using gravimetry, X-ray diffraction (XRD), energy-dispersive X-ray (EDX) spectroscopy, and scanning electron microscopy (SEM). The biological response of the coated samples was evaluated through MTT and resazurin assays. : The coating formed a stable TCP/HEC layer that gradually dissolved over two weeks, converting the surface to magnesium hydroxide, magnesium oxychloride, and magnesium phosphate phases. The formation of brucite, responsible for passivation in the long term, was observed. The coating effectively prevented excessive magnesium oxychloride formation and stabilised magnesium hydroxide after one week. Biological characterization indicated that the coating on AZ31 is safe on the Saos-2 and L929 cell lines. : The TCP-based coating enhances the corrosion resistance of AZ31 alloy in salt solutions, promoting passivating phases and limiting corrosive products, thereby ameliorating biocompatibility issues. This coating demonstrates substantial potential for extending the longevity and functionality of magnesium alloy implants.
: 在盐溶液中，镁合金迅速降解，这限制了它们在未经钝化处理的情况下的使用。AZ31 合金由于其生物降解性和机械性能，在植入物应用中具有很大的应用前景，因此需要有效的耐腐蚀涂层。 : 在这项研究中，设计并评估了一种用于 AZ31 镁合金板的自钝化反应性涂层，使用β-磷酸三钙（TCP）来提高耐腐蚀性和生物相容性。 : 使用 TCP、柠檬酸钠三钠、硝酸镁、羟乙基纤维素（HEC）和氯化钠溶液对 AZ31 板进行浸涂。将涂覆的样品浸入 3.5wt%NaCl 溶液中。使用重量法、X 射线衍射（XRD）、能谱（EDX）和扫描电子显微镜（SEM）分析相演变。通过 MTT 和 Resazurin 测定评估涂覆样品的生物学反应。 : 涂层形成了稳定的 TCP/HEC 层，该层在两周内逐渐溶解，将表面转化为氢氧化镁、氧氯化镁和磷酸镁相。观察到形成了水镁石，这是长期钝化的原因。该涂层在一周后有效地防止了过多的氧氯化镁形成并稳定了氢氧化镁。生物学特性表明，AZ31 上的涂层对 Saos-2 和 L929 细胞系是安全的。 : TCP 基涂层增强了 AZ31 合金在盐溶液中的耐腐蚀性，促进了钝化相的形成并限制了腐蚀性产物的形成，从而改善了生物相容性问题。该涂层为延长镁合金植入物的使用寿命和功能提供了很大的潜力。
