模拟体液中仿生羟基磷灰石超细粉的制备及表征

PREPARATION AND CHARACTERIZATION OF BIOMIMETIC HYDROXYAPATITE IN SIMULATED BODY FLUID

从仿生合成的思路出发,以模拟体液为反应介质,通过磷酸和硝酸钙反应合成了羟基磷灰石(hydroxyapatite,HAP)粉体。利用差热分析、X射线衍射、红外光谱和透射电镜对合成HAP的晶相转变、微观结构和形貌进行了研究,研究了硝酸钙浓度对羟基磷灰石粉体晶相纯度和高温稳定性的影响。结果表明在模拟体液中合成的HAP粉体不需要热处理就含有较多的HAP晶相,经500℃热处理后转变为纯相HAP,硝酸钙浓度为0.2mol/L时所合成的HAP具有很好的纯度和高温稳定性,经1550℃烧结后只有微量αCa3(PO4)2析出;所合成的HAP为纳米颗粒,呈现出球状和短棒状形态,接近于人体骨磷灰石。体外生物活性表明HAP具有较强的诱导Ca,P沉积的能力。

Hydroxyapatite （HAP） powders were synthesized through the reaction between H3 PO4 and Ca（NO3）2 ·4H2O in the medium of simulated body fluid （SBF） by a biomimetic method. The crystal phase transition, microstructure and morphology of the obtained HAP were studied by differential thermal analysis, X-ray diffraction, Fourier transform infrared spectroscopy and transmission electron microscopy. The effects of Ca（NO3 ）2 concentration on the crystal phase purity and high temperature stability of HAP powder were investigated. The results indicate that there is a much greater amount of HAP crystal phase in the HAP powder synthesized in SBF without calcining, and after calcination at 500 ℃ for 1 h the crystal phase of the powders is pure HAP. Particularly, the HAP powder obtained at 0.2 mol/L of Ca（NO3 ）2 concentration has better purity and high temperature stability, and only a few α-Ca3 （POI）2 crystals emerge after calcination at 1 550 ℃. The particle size of the HAP powders is within nanometer scope, with a sphere and short rod-like shape closed to natural bone. The bioactivity test in vitro indicates that the synthesized ttAP powders have a good ability for inducing Ca and P deposition.