Formation and characterization of collagen and hydroxyapatite composite

Abstract

The formation of composite of collagen and hydroxyapatite (HA) was investigated by ex-situ precipitation method. Synthesis of HA was carried out by precipitation of Ca(OH)₂ 1 M and (NH₄)₂.HPO₄ 0.6 M with the molar ratio of Ca/P 1.67, the mixture was exposed to microwave irradiation (450 W) for 45 min. Subsequently, the result was sintered to produce the powders of HA. Verification of HA powders was performed using X-Ray Diffraction (XRD). Chicken collagen was prepared in our laboratory (Physics Department, Universitas Indonesia). Composite was synthesized by ex-situ precipitation method with a mass fraction of collagen and HA was 2:1. The mixture was stirring continuously for 2 h and aged for 20 h at room temperature. The precipitate was dried by freeze-drying method. The composite result was examined by Scanning Electron Microscopy (SEM). XRD pattern of sintered powder shown as HA crystal. The unit cell of HA crystals was evaluated by High Score Plus Program (a=b=9.425 and c=6.884) with the accuracy 98.175% for a and b lattice and 98.406% for c lattice. The collagen had been verified by SDS PAGE as type 1 collagen and the micrograph illustrated the presence of micropores. Based on SEM examination, the composite revealed that HA had been deposited onto collagen and filled part of void space of collagen. The preliminary study will be beneficial for leading the formation of composites of collagen-HA as biomaterials.