On the Application of Oxynitride Thin Films in Biomedicine

The structure, morphology, and roughness of Ti–O–N coatings applied to stainless steel surfaces using reactive magnetron sputtering are investigated for use as biomedical stents. The deposition modes are analyzed with a negative bias applied to the substrate (–60 V), with no bias applied to the substrate, and with varying nitrogen-to-oxygen ratios in the working gas. The resulting coatings exhibited an anatase structure. Analysis by scanning electron microscopy shows a decrease in the grain size of the films with an increase in nitrogen concentration in the working gas when a negative bias (–60 V) is simultaneously applied. In vitro studies conducted on blood donors, involving blood collection followed by plasma separation from erythrocytes through centrifugation at a rate of 1–2 mL/min, demonstrate that the use of Ti–O–N-coated substrates (–60 V) decrease platelet levels and increase hematocrit values.