Synthesis and characterization of bioactive hydroxyapatite–calcite nanocomposite for biomedical applications

• Published in: Journal of colloid and interface science 2010-09, Vol.349 (1), p.56-62
• Main Authors: Kumar, G. Suresh, Girija, E.K., Thamizhavel, A., Yokogawa, Y., Kalkura, S. Narayana
• Format: Article
• Language: English
• Subjects: Biocompatible Materials - chemical synthesis; Biocompatible Materials - chemistry; Calcium carbonate; Calcium Carbonate - chemical synthesis; Calcium Carbonate - chemistry; Chemistry; Citric acid; Citric Acid - chemistry; Colloidal gels. Colloidal sols; Colloidal state and disperse state; Durapatite - chemical synthesis; Durapatite - chemistry; Exact sciences and technology; General and physical chemistry; Hydroxyapatite; Microscopy, Electron, Scanning; Nanocomposite; Nanocomposites; Nanocomposites - chemistry; Nanocomposites - ultrastructure; Nanomaterials; Nanostructure; Phase Transition; Sol gel process; Sol–gel method; Spectroscopy, Fourier Transform Infrared; Synthesis; Thermogravimetry; X-Ray Diffraction
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2010.05.038

Sol–gel synthesis of hydroxyapatite (HA) using citric acid as organic modifier has resulted in the formation of highly bioactive HA–calcite nanocomposite, a superior alternative to HA for biomedical applications when ignored washing process during synthesis. 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.