■铜(Cu)-合金生物材料的抗菌活性在临床应用中显示出巨大的潜力。这里,我们评估了Ti6Al4V-6.5wt%Cu合金在感染骨缺损的体内模型中的成骨作用和抗菌作用,并使用蛋白质组学确定了其负责的蛋白质和途径。
■用Ti6Al4V和Ti6Al4V-6.5wt%Cu植入物填充骨缺损6周后,收集植入物周围的组织和骨骼样本进行放射学检查,Micro-CT,组织学,和骨相关基因表达分析。基于iTRAQ的蛋白质鉴定/定量方法用于分析Ti6Al4V-6.5wt%Cu合金的成骨和抗菌作用。
■成像和组织学结果显示Ti6Al4V合金比Ti6Al4V-6.5wt%Cu合金引起更强的炎症反应;成像和成骨蛋白水平显示Ti6Al4V-6.5wt%Cu合金具有更强的成骨作用。体外实验,我们发现Ti6Al4V-6.5wt%Cu具有明显的抗菌作用,并在早期抑制金黄色葡萄球菌的活性。此外,Ti6Al4V-6.5wt%Cu组形成的细菌生物膜显著低于Ti6Al4V组。对4279种蛋白质进行蛋白质组学筛选,得到35种差异表达的蛋白质供进一步检查,这些蛋白质主要与细胞过程有关,代谢过程,刺激反应,和细胞组件组织。在进一步探索Ti6Al4V-6.5wt%Cu合金成骨矿化机理的基础上,我们发现SDC4和AGRN是与成骨分化和骨矿化相关的前两个靶蛋白。
■Ti6Al4V-6.5wt%Cu合金由于其对抗细菌感染和骨形成的积极作用而显示出作为骨植入材料的巨大潜力。
■目前,钛合金和其他非抗菌金属材料用于骨科内固定手术。我们的研究表明,Ti6Al4V-6.5wt%Cu合金具有良好的体内和体外抗菌和成骨作用。说明Ti6Al4V-6.5wt%Cu合金有可能成为一种新型的抗菌金属材料作为内固定材料,在临床内固定后不断发挥其抗菌作用,降低感染率。
OBJECTIVE: The antibacterial activity of copper (Cu)-alloy biomaterials has shown a great potential in clinical application. Here, we evaluated the osteogenesis and antibacterial effects of Ti6Al4V-6.5wt%Cu alloy in an in vivo model of infected bone defects and determine their responsible proteins and pathways using proteomics.
METHODS: After bone defects were filled with Ti6Al4V and Ti6Al4V-6.5wt%Cu implants for 6 week, the tissue and bone samples around the implants were harvested for radiographic, micro-CT, histological, and bone-related gene expression analyses. An iTRAQ-based protein identification/quantification approach was used to analyze the osteogenic and antibacterial effects of Ti6Al4V-6.5wt%Cu alloy.
RESULTS: Imaging and histological results showed Ti6Al4V alloy induced a stronger inflammatory response than Ti6Al4V-6.5wt%Cu alloy; imaging results and osteogenic protein levels showed Ti6Al4V-6.5wt%Cu alloy exerted a stronger osteogenic effect. In vitro experiment, we found the Ti6Al4V-6.5wt%Cu had significant antibacterial effects and inhibited the activity of Staphylococcus aureus in the early stage. In addition, the bacterial biofilm formed in Ti6Al4V-6.5wt%Cu group was significantly lower than that in Ti6Al4V group. Proteomic screening of 4279 proteins resulted in 35 differentially expressed proteins for further examination which were mainly associated with the cellular process, metabolic process, stimulus response, and cellular component organization. In further exploration of the mechanism of osteogenic mineralization of Ti6Al4V-6.5wt%Cu alloy, we found out SDC4 and AGRN were the top two target proteins associated with osteogenic differentiation and bone mineralization.
CONCLUSIONS: Ti6Al4V-6.5wt%Cu alloy shows a great potential as a bone implant material due to its positive effects against bacterial infection and on bone formation.
UNASSIGNED: At present, titanium alloys and other non-antibacterial metal materials are used in orthopedic internal fixation operations. Our study demonstrates that Ti6Al4V-6.5wt%Cu alloy has good antibacterial and osteogenic effects in vivo and in vitro. This means that Ti6Al4V-6.5wt%Cu alloy may become a new kind of antimicrobial metallic material as internal fixation material to continuously exert its antimicrobial effects and reduce the infection rate after clinical internal fixation.