An optimized powder/suspension based atmospheric Plasma Spray (PS) process, using a Triplex Pro 210 TM torch, was implemented to elaborate Cu:TiO2 surface coatings on stainless steel. Nanometric Degussa P25 TM powder was prepared in a water-based suspension and co-sprayed with a Cu spheroidal powder. The bacterial reduction, evaluated with 1h-exposure to Escherichia Coli (E. Coli), was two times higher for the Cu:TiO2 coating compared to the bare stainless steel substrate. Since the coatings obtained by plasma spray are relatively porous, their antibacterial efficacy was compared to smooth Ag and Cu doped titanium nitride (TiN) films obtained by physical vapor deposition technique (PVD). For the same exposure time, the PVD smooth coatings showed a much lower antibacterial efficacy proving the topography effect on bacterial adhesion.

Metal surface characteristics play a significant role in interacting with their biological environment. Copper surfaces have been identified for their antimicrobial properties. Improvement of antibacterial and antiviral performances can be tailored by surface microstructure modification. Severe plastic deformation is an effective surface modification procedure to improve the mechanical performance of metal surfaces. This technique can be adapted to obtain surface grain refinement and induce surface roughness. In this work, cold spray shot peening is used to modify copper substrate surfaces and study the effects on their antibacterial properties. To modify the grain structure of copper, different shot-peening parameters were examined. The surface roughness and microstructure were investigated by employing optical and scanning electron microscopy. The bactericidal activity of copper substrates after shot peening treatment is discussed and a comparison between the bacterial load on treated (shot-peened surface and cold sprayed copper coating) and untreated surfaces (as-received) is provided. Testing of the surfaces after their exposure to the biological environment demonstrated improved microbial inactivation performances for surfaces that had undergone grain refinement without exceeding a certain roughness value.

The aim of this study is to evaluate the antimicrobial properties of wire-arc-sprayed Cu-Ni-Zn alloy coatings. The biocidal efficacy of the coatings is compared to that of stainless steel and sheet metal using Escherichia Coli as a contaminant. The influence of surface roughness on biocidal activity is investigated as well.

This study assesses the photocatalytic properties of HVOF-sprayed nanostructured TiO 2 coatings, particularly their bactericidal effect. The surfaces of the coatings were lightly polished before being exposed to bacterial solutions of known concentration. The solution was dispensed on the coating and irradiated with white light in 30-minute intervals up to 120 minutes. On polished HVOF-sprayed TiO 2 coatings, 24% of the bacteria were killed after 120 minutes of exposure. On stainless steel controls, the percentage of bacterial cells killed was approximately 6% for most of the exposure times studied.

In this study, vacuum plasma spraying was used to apply hydroxyapatite-silver composite coatings on titanium substrates, which were then exposed to E. coli, Pseudomonas aeruginosa , and Staphylococcus aureus . The coatings exhibited excellent antibacterial performance ( K > 95%) against all three strains, attributed to the release of silver ions. Cytotoxicity, hemolysis, and simulated body fluid immersion tests showed that added silver affects neither the biocompatibility nor bioactivity of the hydroxyapatite, one of the most widely used medical implant materials due to its close chemical structure with natural bone.