Event Abstract Back to Event Synthesis of bioactive coatings on Ti–25Nb–10Zr alloy for hard tissue implants Cosmin Cotrut1, Alina Vladescu2, Ana I. Gherghilescu1 and Irina Titorencu3 1 University Politehnica of Bucharest, Romania 2 National Institute for Research and Development in Optoelectronics, INOE 2000, Romania 3 Institute of Cellular Biology and Pathology "Nicolae Simionescu", Department of Regenerative Medicine, Romania Introduction: The increase in the average age of the population has led to a quickly increasing number of surgical procedures involving prosthesis implantation, because as the human body ages, the load-bearing joints become more prone to disease. This has resulted in an urgent need for improved biomaterials and processing technologies for implants, especially for orthopaedic applications. Ti6Al4V is the most use in medicine, especially for total hip implants, despite of the toxicity of the Al and V elements[1]. In order to solve the problem of Al and V toxicity, many researchers developed a variety of alloys which are mainly consisting of non-toxic and non-allergic elements such as Nb, Ta, Zr, Mo[2]. The aim of this work was to investigate the Ti25Nb10Zr alloys as a possible candidate to replace the Ti6Al4V alloy for orthopedic implants and also to improve their bioactivity by coating with bioactive thins films. Materials and Methods: The Ti25Nb10Zr alloys were casted in a levitation-melting furnace and annealed at 900 °C. The alloy was coated with hydroxyapatite by RF magnetron sputtering method using pure hydroxyapatite target at substrate temperatures ranging from 400 to 800 °C. The surface morphology and the crystallographic structure of the films were investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The corrosion resistance in SBF at 37 ºC was evaluated by potentiodynamic polarization. Additionally, the human osteosarcoma cell line (MG-63) was used to test the biocompatibility of the coatings after 1, 5 and 7 days of culture. Results and Discussions: The results showed that all of the coatings grown uniformly and that the increasing substrate temperature induced an increase in their crystallinity. The Ca/P ratios were in the range 1.67–1.80, indicating the preparation of non stoichiometric and stoichiometric hydroxyapatite. Corrosion performance was improved with the increase of the substrate temperature from 400 °C to 800 °C. The increasing of the substrate temperature up to 700 °C led to the enhancement of the corrosion resistance; no significant differences for temperature variation from 700 to 800 °C were found. Comparing the coatings, after 1 day, no significant changes in cell viability were observed. After 5 days, the cell viability of the coatings increases with deposition temperatures. After 7 days, the best results were found for the samples deposited at 800 °C (Fig.1). Conclusions: The crystalline content and the roughness of HAP films increased with the deposition temperature. The best corrosion resistance was found for the coatings deposited at 700 to 800 °C. All the coatings support the attachment and growth of the osteosarcoma cells with regard to the in vitro test findings. The work was supported under a grant of the Romanian National Authority for Scientific Research grant, CNCS – UEFISCDI, project number PN-II-PT-PCCA-2014-212 and ERA.NET RUS Plus – S&T - ID # 58 (HybrBioScaf).