Sputtered Gum metal thin films showing bacterial inactivation and biocompatibility

•Super-elastic Titanium based thin films were prepared and characterized.•Compactness and microstructure of Sputtered Gum metal thin films were studied.•Antibacterial and biocompatibility were investigated.•Potential practical application of the sputtered films in hospital facilities.

Super-elastic Titanium based thin films Ti-23Nb-0.7Ta-2Zr-(O) (TNTZ-O) and Ti-24Nb-(N) (TN-N) (at.%) were deposited by direct current magnetron sputtering (DCMS) in different reactive atmospheres. The effects of oxygen doping (TNTZ-O) and/or nitrogen doping (TN-N) on the microstructure, mechanical properties and biocompatibility of the as-deposited coatings were investigated. Nano-indentation measurements show that, in both cases, 1 sccm of reactive gas in the mixture is necessary to reach acceptable values of hardness and Young’s modulus. Mechanical properties are considered in relation to the films compactness, the compressive stress and the changes in the grain size. Data on Bacterial inactivation and biocompatibility are reported in this study. The biocompatibility tests showed that O-containing samples led to higher cells proliferation. Bacterial inactivation was concomitant with the observed pH and surface potential changes under light and in the dark. The increased cell fluidity leading to bacterial lysis was followed during the bacterial inactivation time. The increasing cell wall fluidity was attributed to the damage of the bacterial outer cell which losing its capacity to regulate the ions exchange in and out of the bacteria.

Graphical abstractTitanium dioxide based super-elastic gum-metal sputtered films showed bacterial inactivation under low intensity light and mammalian cells biocompatibility in the dark.Figure optionsDownload full-size imageDownload as PowerPoint slide