医用镁合金Glu/LDH涂层结构可控改性、降解机理及生物相容性研究

Biomedical magnesium alloys are promising candidates for degradable orthopedic implants due to their excellent biocompatibility, biodegradability and specific mechanical properties. However, the rapid degradation of magnesium alloys inside the human body leads to unmatched osteogenesis rate which restrict their clinical use. In order to regulate and control the degradation rate of magnesium alloys, as well as to promote the growth of osteoblasts, this program will construct an anticorrosive and biocompatible glutamic acid intercalated LDH layer on the surface of magnesium alloys by adopting the intercalated structure of the LDH and combining with the biological mineralization property of glutamic acid. By examining the influence of the intercalated structure on the ion exchange and corrosion resistance of Glu/LDH coatings, the relationship of the coating composition, microstructure and anticorrosion property will be established. In order to clarify the molecular recognition mechanism and degradation mechanism of the Glu/LDH coatings, the influence of the structure of Glu/LDH coating and the ion exchange of Glu on the selective adsorption of Ca2+ and hydroxyapatite nucleation will be investigated. Eventually, a new coating structure with matched degradation rate of magnesium alloy and the growth of bone tissue will be generated by optimization design of the coating. This program will provide important theoretical and experimental basis for the development and application of biomedical magnesium alloys.

医用镁合金具有良好的生物相容性、可降解特性及优于聚合物的力学性能，是目前最具应用前景的骨植入金属材料。然而，镁合金在人体环境中降解速率过快，其与成骨速率不适配，限制了其广泛应用。为了实现镁合金降解速率可调控与促进成骨细胞生长的双重功能，本项目拟利用LDH插层结构的可调性，结合Glu调控生物矿化速率的特性，在医用Mg-Ca合金表面构建耐蚀且有生物相容性的Glu插层LDH涂层。通过研究插层结构的变化对Glu/LDH离子交换及耐蚀性能的影响规律，建立涂层组成、结构与耐蚀性的关系；为了阐明Glu/LDH涂层界面分子的识别机制及其降解机理，采用体外及体内试验，考察其生物相容性，着重研究Glu/LDH的离子交换行为对Ca2+选择性吸附作用，并确认其对诱导HA形核的影响，获得降解速率与诱导骨生长相匹配的涂层结构。本项目将为医用镁合金的开发和应用提供重要的理论和试验依据。

医用镁合金具有良好的生物相容性、可降解特性及优于聚合物的力学性能，是目前最具应用前景的骨植入金属材料。然而，镁合金在人体环境中降解速率过快，其与成骨速率不适配，限制了其广泛应用。为了实现镁合金降解速率可调控与促进成骨细胞生长的双重功能，本项目利用LDH插层结构的可调性，结合Glu调控生物矿化速率的特性，在医用镁合金表面构建了耐蚀且有生物相容性的Glu插层LDH涂层（Glu/LDH）、水滑石/聚谷氨酸复合涂层（LDH/PGA）、水滑石/聚乳酸复合涂层（LDH/PLA）。考察了Glu/LDH、LDH/PGA、LDH/PLA涂层的结构变化与其耐蚀行为的关联规律，研究了其生物相容性。揭示了LDH/PGA涂层对Ca2+选择性吸附作用，构建了涂层结构的变化对LDH/PGA耐蚀性能的影响规律；阐明了Glu/LDH涂层界面分子的识别机制及其降解机理，采用体外试验，考察了其生物相容性，从而获得了降解速率与诱导骨生长相匹配的涂层结构。本项目为医用镁合金的开发和应用提供了重要的理论和试验依据。