磷酸缓冲液快速洗涤纳米羟基磷灰石

目前广泛应用于生物医学领域的合成纳米羟基磷灰石大多数都是在pH>10的碱性条件下合成的，这就导致了在合成后期需要花大量时间、消耗大量水清洗羟基磷灰石以除去其碱性，影响后续实验研究和生产进程。本文基于中性磷酸缓冲液（PBS）建立了一种快速洗涤羟基磷灰石的方法。采用沉淀法以硝酸钙和磷酸三钠为原料制备了羟基磷灰石（HA），用磷酸氢二钠和磷酸二氢钠配制了pH=7的PBS，采用所配制的PBS快速洗涤羟基磷灰石至中性，同时通过传统洗涤流程清洗另一批次羟基磷灰石至中性。通过TEM、XRD、IR、TG分析了两种洗涤方法生成产物的晶粒形貌、晶体尺寸及化学成分。结果表明：PBS快速洗涤法得到的产物与传统方法洗涤的羟基磷灰石的成分、晶体结构、尺寸及产物纯度无明显区别，但PBS洗涤可在一定程度上提高了HA晶体的结晶完整性和热稳定性。本文提出的PBS快速洗涤法节约清洗HA的去离子水达80%以上，大幅缩短洗涤周期，有望在实验室及工业生产中提高纳米羟基磷灰石的产出速率和压缩产出成本。

Rapid wash of nano-hydroxyapatite with phosphate buffer solution

Synthetic nano-sized hydroxyapatite, which is widely used in biomedical engineering, is commonly prepared at pH>10, leading to long time and large amounts of water to wash the fabricated hydroxyapatite so as to remove its alkaline before further processing. In this paper, we developed a method for rapid washing hydroxyapatite by using neutral phosphate buffer (PBS) as the washing solution. Firstly, hydroxyapatite (HA) was prepared by precipitation using calcium nitrate and trisodium phosphate as raw materials. Then the hydroxyapatite was quickly washed with the formulated PBS to neutral, while another hydroxyapatite sample was neutralized by washing with deionized water based on the conventional washing procedure. The morphology, particle size and chemical composition of the samples washed by the two methods were analyzed by transmission electron microscope, X-ray diffraction, infrared spectroscopy and thermogravimetry. The results showed that the above-mentioned properties of the products obtained by the two methods did not show significant difference, although the HA crystals washed with PBS showed improved crystal integrity and thermal stability. Notably, the rapid washing method with PBS can save more than 80% of deionized water and shorten the washing cycle from 10 day to about 8 hour in comparison with the conventional washing method. The rapid washing method proposed in this paper is expected to be able to greatly increase the yield and lower the cost of nano-hydroxyapatite in laboratory and industrial production.