One- and Three-Dimensional Growth of Hydroxyapatite Nanowires during Sol鈥揋el鈥揌ydrothermal Synthesis
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- 作者：Daniel O. Costa ; S. Jeffrey Dixon ; Amin S. Rizkalla
- 刊名：ACS Applied Materials & Interfaces
- 出版年：2012
- 出版时间：March 28, 2012
- 年：2012
- 卷：4
- 期：3
- 页码：1490-1499
- 全文大小：683K
- 年卷期：v.4,no.3(March 28, 2012)
- ISSN：1944-8252
文摘
Nanoscale hydroxyapatite (HA) is an optimal candidate biomaterial for bone tissue engineering because of its bioactive and osteoconductive properties. In this study, micro- and nanoscale HA particles with rod- and wirelike morphology were synthesized by a novel sol鈥揼el鈥揾ydrothermal process. Sol鈥揼el chemistry was used to produce a dry gel containing amorphous calcium phosphate (ACP), which was used as a precursor material in a hydrothermal process. The sol鈥揼el鈥揾ydrothermal products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) to determine particle morphology, crystal structure, and the presence of chemical functional groups. A pure HA crystal was synthesized, which underwent both one- and three-dimensional growth, resulting in tunable microrod and nanorod, and wire morphologies. The effects of solution pH and reaction time on particle diameter and length were assessed. Particle diameter ranged from 25 to 800 nm and decreased with an increase in solution pH, whereas both particle length and diameter increased as the hydrothermal process was prolonged. Nanowire HA powders (10鈥?0 wt %) were mixed with poly(蔚-caprolactone) (PCL) to produce PCL/HA composites. Fracture surfaces of PCL/HA composites showed a well-dispersed and homogeneous distribution of HA nanowires within the PCL matrix. Mechanical testing revealed a significant (p < 0.05) increase in the Young鈥檚 and compressive moduli of PCL/HA composites compared to PCL alone, with 50 wt % HA producing a 3-fold increase in Young鈥檚 modulus from 193 to 665 MPa and 2-fold increase in compressive modulus from 230 to 487 MPa. These HA nanowires can be used to reinforce polymer composites and are excellent biomaterials for tissue engineering of bone.