Abstract
The paper presents new results of manufacturing coatings by magnetron sputtering to improve the functional properties of joint endoprostheses. The antibacterial properties of Ti-Cu and Ta-Cu coatings deposited by DC multi-magnetron sputtering on Ti6Al4V alloy substrates subjected of gas-abrasive treatment have been investigated. The roughness of the substrate was measured by optical profilometry. The coating hardness and elastic modulus were estimated by nanoindentation methods; the adhesion characteristics were assessed by Rockwell test. Scanning electron microscopy with energy-dispersive X-ray analysis verified the application of coatings with 25 at.% Cu, at thicknesses of 2 μm and 10 μm to roughened Ti6Al4V alloy. All coatings demonstrated sufficient adhesion, whereas Ta-Cu coatings generally revealed higher hardness, while the elastic modulus decreased with increasing coating thickness. Staphylococcus aureus strains were used for in vitro study of the antibacterial properties of Ti-Cu and Ta-Cu coatings. The largest zones of inhibition of bacteria S. aureus 23 mm were observed for 10 µm Ta-Cu coating thickness. The release dynamics of Cu ions from Ta-Cu and Ti-Cu coatings into physiological solution analyzed over seven days via inductively coupled plasma mass spectrometry, matched the inhibition zone growth. The Ti-Cu and Ta-Cu coatings of 2 µm thickness provided weaker antibacterial effect. The optimal parameters of magnetron sputtering of antibacterial Ti-Cu and Ta-Cu coatings on Ti6Al4 alloy substrates were selected. These findings support the potential of these coatings in developing endoprosthesis implants with enhanced antimicrobial and wear-resistant properties