Tailoring the antibacterial-cytocompatibility properties of DLC coatings with Ag and TiO2 co-incorporation by DC-PECVD technique with active screen

Pure DLC and DLC coatings containing titanium dioxide (TiO 2 ) and silver (Ag) are widely used to recover surfaces and prevent bacterial proliferation in biomedical devices. This work aims to study the cell viability and antibacterial effect of Ag and TiO 2 single- and multiple-incorporation in DLC coatings deposited on the Ti6Al4V alloy surface using the modified DC-PECVD technique with an active screen as an additional cathode, thereby allowing greater ion confinement within the deposition chamber. The nanoparticles were inserted into the vacuum chamber using a pulsed valve. The results showed that the DLC-TiO 2 :Ag (30:70) samples exhibited enhanced cell viability compared to the DLC-Ag coating, while maintaining an effective antibacterial effect, providing valuable insights into the potential of these coatings for biomedical applications. Cell viability values were 127%, 98%, 96%, 93%, 90% e 85% for the Ti6Al4V, DLC-TiO 2 , DLC-TiO 2 :Ag (30:70), DLC-TiO 2 :Ag (70:30), DLC, and DLC-Ag samples, respectively. Considering the Ti6Al4V alloy with no coating, the percentual reduction in the bacteria number was 44.50, 45.98, 43.02, 58.10, and 58.34% for the samples DLC, DLC:TiO 2 , DLC-TiO 2 :Ag (70:30), DLC-TiO 2 :Ag (30:70), and DLC Ag, respectively. These findings highlight an optimal compositional window in Ag and TiO₂ multiple incorporated DLC coatings, where antibacterial activity and cytocompatibility can be simultaneously achieved, offering a promising route for the design of multifunctional surfaces for biomedical applications.