National Engineering Research Center of Light Alloy Net Forming and Key State Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
National Engineering Research Center of Light Alloy Net Forming and Key State Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China; Department of Bone & Joint Surgery, National & Local Joint Engineering Research Center of Orthopedic Biomaterials, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Peking University Shenzhen Hospital, Shenzhen 518036, China.
Mater Sci Eng C Mater Biol Appl. 2020 Jun;111:110779. doi: 10.1016/j.msec.2020.110779. Epub 2020 Feb 26.
Development of bone graft substitutes with appropriate integration of mechanical, biodegradable, and biofunctional properties, which promote bone formation while simultaneously preventing implant-associated infections, remains a great challenge. Herein we designed and synthesized a brushite/AgPO-coated Mg-Nd-Zn-Zr scaffolds through chemical solution deposition of a composite coating onto the fluorinated Mg-based scaffolds generated with template replication method. The coated Mg-based open-porous scaffolds exhibit hierarchically-structured surface with cube-shaped AgPO nanoparticles uniformly distributed on top of microsized brushite grains. Immersion test reveals that the initial degradation rate of the coated scaffolds could be reduced by ~81% compared to the original scaffolds. The mean corrosion rate in 4 weeks falls into 0.10-0.15 mm/year to meet clinical requirements. The compatibility and ALP activity of cells grown in the extracts from the coated Mg-based scaffolds were increased compared with Ti control and original scaffolds, mainly due to the favorable microenvironment generated by Mg biodegradation. Besides, the coated Mg-based scaffold demonstrated potent antimicrobial activity via the synergistic actions of alkaline degradation products of Mg and the Ag species in the coating, achieving >99.5% antibacterial rate against both gram-positive and gram-negative bacteria with relatively low silver content. Taken together, this study presents a new candidate of brushite/AgPO-coated Mg-based scaffold with appropriate degradation characteristics, cytocompatibility, and antimicrobial activities for bone tissue engineering applications.
开发具有适当机械性能、生物降解性能和生物功能性能整合的骨移植替代物，在促进骨形成的同时防止植入物相关感染，仍然是一个巨大的挑战。在此，我们通过化学溶液沉积法将复合涂层涂覆在模板复制法制备的氟化 Mg 基支架上，设计并合成了磷酸氢钙/AgPO 涂层的 Mg-Nd-Zn-Zr 支架。涂覆的 Mg 基开式多孔支架具有分级结构的表面，其表面均匀分布着立方体形的 AgPO 纳米颗粒和微尺度的磷酸氢钙颗粒。浸泡实验表明，与原始支架相比，涂层支架的初始降解速率可降低约 81%。在 4 周内的平均腐蚀速率落入 0.10-0.15mm/年，满足临床要求。与 Ti 对照和原始支架相比，在涂层 Mg 基支架浸提液中培养的细胞的相容性和 ALP 活性提高，主要是由于 Mg 生物降解产生的有利微环境。此外，涂层 Mg 基支架通过 Mg 碱性降解产物和涂层中 Ag 物种的协同作用表现出强大的抗菌活性，对革兰氏阳性菌和革兰氏阴性菌的抗菌率均达到>99.5%，而银含量相对较低。综上所述，本研究提出了一种新的具有适当降解特性、细胞相容性和抗菌活性的磷酸氢钙/AgPO 涂层 Mg 基支架，可用于骨组织工程应用。
