Strontium doped calcium phosphate biomimetic coatings on Ti6Al4V plates

Avcı, Muhammed
In this study, strontium was added into the structure of calcium phosphate and coated on Ti6Al4V plates with using biomimetic method. In order to form strontium doped calcium phosphate coatings, 2×SBF with strontium was made with adding SrCl2 while preparing normal 2×SBF. Ti6Al4V plates were used as substrates and their surfaces were abraded and oxidized with pretreatment. These plates were coated in pure (no Sr added), 0.15mM, 1mM and 5mM Sr added 2×SBF. Surface of the coated plates was characterized and analyzed starting at 3rd day of immersion till 18th day by using EDS, SEM, XRD, ICP-MS, FTIR and Raman spectroscopy. Human osteosarcoma cells were used for in vitro analyses. In order to analyze durability of coatings, an aging procedure was applied. According to the SEM results, nucleation already started on third day of coating and by increased immersion time, precipitation increased on nucleation sites. Surface analyses of samples soaked in 5mM Sr added 2×SBF at 6th day of immersion showed that no significant coating was formed on substrate plates and therefore, immersion of 5mM Sr added samples was terminated. EDS and ICP-MS analyses showed that Sr has successfully incorporated into the calcium phosphate structure for both 1mM and 0.15mM Sr added samples. In addition, EDS analyses showed that, with immersion time increased, Ca/P ratio of coatings increased for all types of samples. XRD, Raman and FTIR analyses showed that crystallinity of calcium phosphate coatings was increased with immersing time and hydroxyapatite structure started to form. Crystallinity was seen in the highest for pure samples and higher for 0.15mM than 1mM Sr added samples. In case of in vitro analyses, both aged and non-aged coated samples had similar SEM results. Although cell proliferation was observed slightly higher for pure and 0.15mM Sr added samples than 1mM Sr added samples, it was observed for all types of samples. MTT cell viability test results showed that, pure, 0.15mM Sr added and 1mM Sr added samples had similar cell viability and no significant toxicity was found for these samples.


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Citation Formats
M. Avcı, “Strontium doped calcium phosphate biomimetic coatings on Ti6Al4V plates,” M.S. - Master of Science, Middle East Technical University, 2015.