Bioactive Structure Development on Ti/Zr/Ti/Si and Ti/Cu/Ti/Si Thin Films via Laser Irradiation

The fundamental trend in the development of biocompatible materials such as thin films is to enhance their characteristics to guarantee the operation of these systems without posing any risks to human health [1-6]. Therefore, this study aimed to investigate the relationship between the chemical composition, morphology, microstructural and biocompatibility of materials based on titanium thin layers that were obtained through an unconventional process of physical deposition from the vapor phase using a multidisciplinary approach. On the other hand, irradiation with ultrashort laser pulses in the pico- and femtosecond time range was carried out to more thoroughly investigate the adherence of cell cultures on the materials thus generated, as well as the formation of micro- and nanostructures. The deposited and laser-modified thin layers were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM) and optical profilometry. The uniformity of the deposited layers in the cross-section was confirmed by scanning transmission electron microscopy (STEM), whereby the depth profiles were used for the determination of the elemental composition and spatial distribution of the elements. Chemical analysis of the surface of Ti/Cu/Ti and Ti/Zr/Ti thin layers revealed enhanced oxidation following by laser irradiation. Furthermore, STEM/EDS research revealed that elements of the subsurface layer diffused as a result of laser radiation, and zirconium and copper were consistently distributed across the layer’s depth, with a concentration of around 1-2 percent by weight. The results of the MTT test and the analysis of morphological changes showed that the laser-modified thin layers are not cytotoxic. The mean viability of MRC-5 cells in contact with laser-modified Ti/Zr/Ti and Ti/Cu/Ti is higher than the mean viability of cells without thin layers as well as the control sample (pure titanium).