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Ag and Ag x O thin films were deposited by non-reactive and reactive pulsed DC magnetron sputtering, respectively, with the final propose of functionalizing the SS316L substrate with antibacterial properties. The coatings were characterized chemically, physically and structurally. The coatings nanostructure was assessed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), while the coatings morphology was determined by scanning electron microscopy (SEM). The XRD and XPS analyses suggested that Ag thin film is composed by metallic Ag, which crystallizes in fcc-Ag phase, while the Ag x O thin film showed both metallic Ag and Ag O bonds, which crystalize in fcc-Ag and silver oxide phases. The SEM results revealed that Ag thin film formed a continuous layer, while Ag x O layer was composed of islands with hundreds of nanometers surrounded by small nanoparticles with tens of nanometers. The surface wettability and surface tension parameters were determined by contact angle measurements, being found that Ag and Ag x O surfaces showed very similar behavior, with all the surfaces showing a hydrophobic character. In order to verify the antibacterial behavior of the coatings, halo inhibition zone tests were realized for Staphylococcus epidermidis and Staphylococcus aureus. Ag coatings did not show antibacterial behavior, contrarily to Ag x O coating, which presented antibacterial properties against the studied bacteria. The presence of silver oxide phase along with the development of different morphology was pointed as the main factors in the origin of the antibacterial effect found in Ag x O thin film. The present study demonstrated that Ag x O coating presented antibacterial behavior and its application in cardiovascular stents is promising.

Nanoporous tantalum oxide (Ta2O5) attraction has been increasing due its high variety of applications, from protective coatings, photocatalysts to biomedical devices. Anodization is a surface modification technique, inexpensive, versatile and easily scalable, widely used to produce these nanostructures. In this work, Ta2O5 nanoporous surface were produced by anodization in a non-aqueous HF-free electrolyte composed by ethylene glycol, water and ammonium fluoride (NH4F), for different anodization parameters (electrolyte concentration, applied potential and time) and comparing a two-step with one-step anodization process. The surface morphology of each sample was investigated by scanning electron microscopy (SEM) and the sample with the optimized nanostructure was characterized in terms of cross-section morphology, chemical composition and crystalline structure. The concentration of NH4F and applied potential demonstrated a

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In the sensors field, titanium based coatings are being used for the acquisition/application of electrical signals from/to piezoelectric materials. In this particular case, sensors are used to detect dynamic mechanical loads at early stages after intervention of problems associated with prostheses implantation. The aim of this work is to select an adequate electrode for sensor applications capable, in an initial stage to avoid bone cell adhesion, but at a long stage, permit osteointegration and osteoinduction. This work reports on the evaluation of osteoblast MC3T3-E1 cells behavior in terms of proliferation, adhesion and long-term differentiation of two different systems used as sensor electrodes: Ti1-xAgx and Ag-TiNx deposited by d.c. and pulsed magnetron sputtering at room temperature on poly(vinylidene fluoride) (PVDF). The results indicated an improved effect of Ag-TiNx electrodes compared with Ti1-xAgx and TiN, in terms of diminished cell adhesion and proliferation at an initial cell culture stage. Nevertheless, when cell culture time is longer, cells grown onto Ag-TiNx electrodes are capable to proliferate and also differentiate at proper rates, indicating the suitability of this coating for sensor application in prostheses devices. Thus, the Ag-TiNx system was considered the most promising electrode for tissue engineering applications in the design of sensors for prostheses to detect dynamic mechanical loads.