Studies of doped biomimetic nano-hydroxyapatite/polymer matrix Composites for applications in biomedical field

Every year, millions of people are suffering from bone defect arising from trauma, tumor or bone diseases. Therefore, there is a growing need for the development of biocomposites with excellent bioactivity and compatibility. In this study, nano-hydroxyapatite was elaborated by using polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) under mild temperature condition. Comparison with pure nano-hydroxyapatite prepared by precipitation method was investigated. The main goal is to highlight the effects of the introduction of polymers on the physico-chemical properties, morphology and on the chemical reactivity and bioactivity for applications in bony surgery. TEM showed a nanosphere hydroxyapatite with an average diameter 45 nm obtained by using PVA. Nano-rods HA with an average dimensions 13 nm width and 156 nm length were obtained by using, PVP. “In-vitro” physiological stability and solubility of the investigated samples was performed by soaking powder in Simulated Body Fluid under physiological condition. Characterization by XRD, FT-IR SEM-EDS and ICP-OES were performed to identify phases, microstructure and then the chemical reactivity and bioactivity after soaking in SBF to evaluate the bioactivity kinetics. Crystals on the polymer fibril matrix exhibited certain orientation. Bone like apatite layer onto the surfaces is confirmed after post immersion in SBF by FT-IR, SEM-EDS and XRD. The polymer matrix controlled the dissolution precipitation reactivity with specific rate without change on the pH of the surrounding physiological body fluid. Key-words: Nano-Hydroxyapatite, bioactivity, biomimetic, polyvinyl alcohol, polyvinylpyrrolidone, Precipitation, Polymer matix composite, “in vitro” assay