Department of Chemical and Biochemical Engineering, Faculty of Engineering, The University of Western Ontario, London, Ontario, Canada N6A 5B9.
ACS Appl Mater Interfaces. 2012 Mar;4(3):1490-9. doi: 10.1021/am201735k. Epub 2012 Feb 15.
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-gel-hydrothermal process. Sol-gel 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-gel-hydrothermal 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 (10-50 wt %) were mixed with poly(ε-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's and compressive moduli of PCL/HA composites compared to PCL alone, with 50 wt % HA producing a 3-fold increase in Young's 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.
纳米级羟基磷灰石（HA）因其具有生物活性和骨诱导性而成为骨组织工程的最佳候选生物材料。在这项研究中，通过一种新颖的溶胶-凝胶-水热法合成了具有棒状和线状形态的微纳级 HA 颗粒。溶胶-凝胶化学用于生产含有无定形磷酸钙（ACP）的干凝胶，该凝胶用作水热过程中的前体材料。通过扫描电子显微镜（SEM）、X 射线衍射（XRD）和傅里叶变换红外光谱（FTIR）对溶胶-凝胶-水热产物进行了表征，以确定颗粒形态、晶体结构和化学官能团的存在。合成了纯 HA 晶体，其经历了一维和三维生长，从而产生了可调谐的微棒和纳米棒以及线状形态。评估了溶液 pH 值和反应时间对粒径和长度的影响。粒径范围为 25-800nm，并随溶液 pH 值的增加而减小，而随着水热过程的延长，颗粒长度和直径均增加。将纳米线 HA 粉末（10-50wt%）与聚己内酯（PCL）混合，制备 PCL/HA 复合材料。PCL/HA 复合材料的断裂表面显示出 HA 纳米线在 PCL 基质中良好分散和均匀分布。力学测试表明，与纯 PCL 相比，PCL/HA 复合材料的杨氏模量和压缩模量均显著（p<0.05）增加，其中 50wt%HA 使杨氏模量从 193MPa 增加到 665MPa，压缩模量从 230MPa 增加到 487MPa，增加了 3 倍和 2 倍。这些 HA 纳米线可用作聚合物复合材料的增强材料，是骨组织工程的优异生物材料。
