title: Synthesis and characterization of bioactive hydroxyapatite-calcite nanocomposite for biomedical applications.
abstract: In a number of recent reports on the synthesis of hydroxyapatite (HA) by sol-gel method using citric acid as an organic modifier, washing was an essential step to remove the byproducts and citric acid. In the present study we made an attempt to synthesize HA by sol-gel method in the presence of citric acid, wherein we have employed calcination technique instead of the conventional washing process. The products thus obtained were analyzed by X-ray diffraction (XRD), Fourier Transform-Infrared (FT-IR) spectroscopy, thermogravimetry and scanning electron microscopy which confirmed the formation of a nanocomposite of HA and CaCO(3) (calcite) when citric acid was added during synthesis. HA is known to be bioactive and bioresorbable but the rates are too low. On the other hand, CaCO(3) is highly biodegradable. The combination of HA and CaCO(3) compromised the demerits of each others. The dissolved Ca ions from CaCO(3) enhanced the supersaturation of the surrounding fluid which resulted in higher bioactivity of HA.
authors.affiliation: Department of Physics, Periyar University, Salem 636 011, India.
authors.forename: G Suresh
authors.initials: GS
authors.lastname: Kumar
authors.forename: E K
authors.initials: EK
authors.lastname: Girija
authors.forename: A
authors.initials: A
authors.lastname: Thamizhavel
authors.forename: Y
authors.initials: Y
authors.lastname: Yokogawa
authors.forename: S Narayana
authors.initials: SN
authors.lastname: Kalkura
mesh_terms: D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry; D002119:Calcium Carbonate / Q000138:chemical synthesis* / Q000737:chemistry; D019343:Citric Acid / Q000737:chemistry; D017886:Durapatite / Q000138:chemical synthesis* / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D044367:Phase Transition; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D019343:Citric Acid; D017886:Durapatite; D002119:Calcium Carbonate