Fabrication and evaluation of low crystallinity and transparent hydroxyapatite via soft processing

羟基磷灰石(HAP)表面对细胞黏附蛋白等生物活性物质具有良好的吸附能力，因此具有良好的细胞黏附性能。虽然透明的HAP陶瓷是通过高温高压烧结工艺制备的，但烧结后的HAP的组成和结构变化有限，与天然骨磷灰石有很大的不同。本研究通过纳米粒子的低温组装条件，制备了结晶度较低的透明羟基磷灰石。低结晶度透明羟基磷灰石颗粒间有纳米级的气孔，结晶度低，比表面积大，与传统的透明羟基磷灰石陶瓷有很大的不同。光学显微镜可以直接观察到低结晶度透明羟基磷灰石上细胞的黏附和增殖，并且透明羟基磷灰石的纳米结构对细胞的黏附和增殖有显著的影响。

Hydroxyapatite (HAp) exhibits excellent cell adhesion because of favorable adsorption capacity of its surface for bioactive substances such as cell-adhesive proteins. Although transparent HAp ceramics are prepared via a high-temperature and high-pressure sintering process, the composition and structure of the sintered HAp have limited variety, and are largely different from natural bone apatite. In this study, a low-crystallinity transparent HAp was developed via a low-temperature nanoparticle assembling conditions. The low-crystallinity transparent HAp developed here had nanosized pores among the particles, and showed low crystallinity with high surface area, which is largely different from the conventional transparent HAp sintered ceramics. Cell adhesion and proliferation on the low-crystallinity transparent HAp could be directly observed with an optical microscope, and significantly influenced by the nanostructure of the transparent HAp.