Geng Zhen, Yuan Qin, Zhuo Xianglong, Li Zhaoyang, Cui Zhenduo, Zhu Shengli, Liang Yanqin, Liu Yunde, Bao Huijing, Li Xue, Huo Qianyu, Yang Xianjin
Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072, China.
School of Laboratory Medicine, Tianjin Medical University, Tianjin 300072, China.
Nanomaterials (Basel). 2017 Feb 15;7(2):38. doi: 10.3390/nano7020038.
Nanosized hydroxyapatite (HA) is a promising candidate for a substitute for apatite in bone in biomedical applications. Furthermore, due to its excellent bone bioactivity, nanosized strontium-substituted HA (SrHA) has aroused intensive interest. However, the size effects of these nanoparticles on cellular bioactivity should be considered. In this study, nanosized HA and SrHA with different dimensions and crystallization were synthesized by hydrothermal methods. The phase, crystallization and chemical composition were analyzed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR), respectively. The morphology was observed under field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The degradation behaviors of the samples were monitored by determining the ions release profile with inductively coupled plasma mass spectrometry (ICP-MS). The releasing behavior of Ca and Sr showed that the degradation rate was proportional to the specific surface area and inversely proportional to crystallization. The in vitro experiment evaluated by MG63 cells showed that SrHA nanorods with a length greater than 100 nm had the best biological performance both in cell proliferation and differentiation (* < 0.05 compared with HA-1 and SrHA-1; * < 0.01 compared with HA-2). In addition, HA nanoparticles with a lower aspect ratio had better bioactivity than higher ones (* < 0.05). This study demonstrated that nanosized HA and SrHA with subtle differences (including dimensions, crystallization, specific surface area, and degradation rate) could affect the cellular growth and thus might have an impact on bone growth in vivo. This work provides a view of the role of nano-HAs as ideal biocompatible materials in future clinical applications.
纳米羟基磷灰石（HA）是生物医学应用中替代骨中磷灰石的一种很有前景的材料。此外，由于其优异的骨生物活性，纳米锶取代羟基磷灰石（SrHA）引起了广泛关注。然而，应考虑这些纳米颗粒的尺寸效应对细胞生物活性的影响。在本研究中，采用水热法合成了具有不同尺寸和结晶度的纳米HA和SrHA。分别通过X射线衍射（XRD）和傅里叶变换红外光谱（FT-IR）分析了其物相、结晶度和化学成分。在场发射扫描电子显微镜（FE-SEM）和透射电子显微镜（TEM）下观察其形貌。通过电感耦合等离子体质谱（ICP-MS）测定离子释放曲线来监测样品的降解行为。Ca和Sr的释放行为表明，降解速率与比表面积成正比，与结晶度成反比。通过MG63细胞进行的体外实验表明，长度大于100 nm的SrHA纳米棒在细胞增殖和分化方面具有最佳的生物学性能（与HA-1和SrHA-1相比，* < 0.05；与HA-2相比，* < 0.01）。此外，长径比低的HA纳米颗粒比长径比高的具有更好的生物活性（* < 0.05）。本研究表明，纳米HA和SrHA的细微差异（包括尺寸、结晶度、比表面积和降解速率）会影响细胞生长，进而可能对体内骨生长产生影响。这项工作为纳米HA作为未来临床应用中理想的生物相容性材料的作用提供了一个视角。
