The Antibacterial Activity Of Cu-Ti-O Nanotube Arrays And Their Effects On Endothelial Cells And Osteoblasts

Titanium?Ti?and its alloys have been widely used as orthopedic implant materials on account of their excellent biocompatibility,corrosion resistance,mechanical properties and magnetic resonance imaging?MRI?compatibility.But bacterial infection,loosening and other postoperative complications of orthopedic implants trouble both doctors and patients all the time.Nanoscale topography may interact with a variety of cells more effectively than conventional micro-or macrostructures,among which TiO₂ nanotube arrays?NTAs?have drawn extensively attention,the reason is that TiO₂ nanotube arrays with proper dimensions not only can promote osteogenic differentiation of osteoblasts,but also promote angiogenesis.However,poor antibacterial activity of TiO₂ nanotube array invalidates them to combat bacterial infections.Accordingly,the present work incorporated copper?Cu?into TiO₂ NTAs?Cu-Ti-O NTAs?through anodizing magnetron-sputtered TiCu coatings with different Cu contents on pure titanium?Ti?.And their long-term antibacterial activity,cytocompatibility,and effects on the endothelial cells and osteoblasts are also investigated.The results are as follows:?1?TiCu composite coatings are fabricated on pure Ti using magnetron sputtering,Cu concentration could be controlled between 0 at.% and 20.04 at.%.?2?Ordered Cu-Ti-O NTAs can be produced under 15.14 at.% of Cu content in TiCu coatings and nanoporous structure is fabricated when the Cu content comes to 20.04 at.% in TiCu coatings.?3?Continuous release of Cu²⁺ from Cu-Ti-O NTAs makes them possess excellent long-term antibacterial ability against Staphylococcus aureus?S.aureus?.?4?All nanotube array surfaces have no influence on adhesion and activity of endothelial cells?ECs?.Meanwhile,Cu-Ti-O NTAs can up-regulate nitric oxide?NO?synthesis and vascular endothelial growth factors?VEGF?secretion of ECs both on sample surfaces and their ionic extracts compared with TiO₂NTAs?control?.Furthermore,in vitro angiogenesis activity is also enhanced in ionic extracts of Cu-Ti-O NTAs compared with control.?5?Cu-Ti-O NTAs have no significant effect on alkaline phosphatase activity.In the early stage of inducing differentiation,Cu-Ti-O NTAs can promote the deposition of collagen and inhibit matrix mineralization in short time due to the increase of Cu²⁺ concentration,but this phenomenon becomesinsignificant and even disappears finally with the extension of inducing culture time.Therefore,good long-term antibacterial ability,favorable angiogenesis and osteogenic activity render Cu-Ti-O NTAs promising as implant coatings.