Background: Biomaterials in the form of thin-film coatings as-deposited on different substrates are nowadays increasingly popular. In particular coatings based on a combination of biocompatible materials (eg. titanium) with metals of high biological activity (eg. copper) have a potentially wide range of applications as active films, intended for various types of medical devices.
Objectives: The aim of this study was to present a method for preparation and analysis of the properties of Cu-Ti thin films, in particular their biological activity in connection with the properties of the surface.
Material and methods: The films were prepared by magnetron sputtering method with the aid of an innovative four-target apparatus. During deposition process two metallic targets (copper and titanium) were sputtered under an argon atmosphere. Material composition of produced coatings was characterized by scanning electron microscope equipped with an adapter for energy dispersive spectroscopy. Moreover, the surface microstructure and roughness of coatings was characterized based on three-dimensional surface profiles, which were obtained with the aid of optical profilometer. The research was also carried out by investigations of surface wettability on the apparatus for measurements of contact angle. Characterization of Cu-Ti surface properties was also expanded by microbiological tests involving Staphylococcus aureus (PCM 2602) bacteria and investigations of cytotoxicity with L 929 (NCTC clone 929) cell line.
Results: Measurements have shown that the film was composed of 71% at. Cu and 29% at. Ti. The analysis of surface topography has shown that the surface of Cu-Ti thin film was very uniform with roughness in range of nanometers. It was found that as-deposited film is hydrophilic. Obtained results has shown that as-deposited film had a very good bactericidal properties and it was cytotoxic. This effect was associated with the migration of copper ions, which was the most intense at the edge of the sample.
Conclusions: The results presented in this paper testify that manufactured Cu-Ti thin films may find practical application in the industry as a bioactive coating.