Silicon-substituted hydroxyapatite nanocomposite: Synthesis, characterization and in vitro bioactivity study in Human Serum Albumin

Nano hydroxyapatite and Silicon-substituted hydroxyapatite nanocomposites with various amount of Si contents (0, 2, 4 and 6 mole % as named as HS0, HS2, HS4 and HS6) were prepared via in situ hybridization method and were analyzed by XRD, FTIR, SEM and AFM techniques. Size distribution of the products demonstrated that hydroxyapatite particles size was between 2 and 53.5 nm with further mean size about 23 nm, while these results, were found to be present around 45, 32 and 38 nm for HS2, HS4 and HS6 respectively. The XRD results specified that some change occurred in the hydroxyapatite lattice with varying Si content in composites samples and explained incorporation of silicon did not appear significantly affect upon the diffraction pattern. SEM micrograph indicated many small particle crystallites existed in the aggregated surface that improved surface modification of composite products that might be due to the high solubility of the nanoparticles in the organic solvents. Subsequently soaking in Human Serum Albumin caused tiny particles observation in a new formation, as the new form of apatite layer covered the samples. In addition, it is quite obvious that the all peaks in FTIR remained after immersion, while peaks intensity was decreased.