造孔剂和发泡剂结合法制备氟化羟基磷灰石多孔支架研究

本研究采用添加造孔剂和发泡剂相结合法制备多孔氟化羟基磷灰石, 合成具有大孔与小孔套连、3D方向上分布的多孔支架。通过化学沉淀法制备了氟化羟基磷灰石(FHA)粉体, 以碳酸氢铵为发泡剂、PMMA为造孔剂, 通过烘干和烧结工艺制备孔洞均匀且相互贯通、坯体致密的多孔支架。经X射线衍射分析, 支架的相组成是FHA和β-TCP。SEM观察结果显示支架孔洞形貌规整、大孔尺寸100~400 µm, 小孔尺寸10~50 µm。以HA和β-TCP为原料对造孔方法的普适性进行验证, 并对支架孔的形成及其影响因素进行了分析。

A Novel Technique to Prepare Porous 3D Fluoridated Hydroxyapatite Scaffold Using Pore-forming and Foaming Agents

A novel technology using pore-forming agent and foaming agent was developed to prepare multi-porous fluoridate hydroxyapatite scaffolds. With this technology, scaffolds were produced with uniform and highly interconnected pores in which large pores containing small ones on their walls distributing along 3-dimension. First, the precursor, FHA powder, was prepared by chemical precipitation method. Then it was used to form scaffold through heat treatments by adding ammonium bicarbonate as foaming agent and polymethyl methacrylate as pore-forming agent, and a dense frame of multi-porous structure was obtained. Investigated by X-ray diffraction (XRD), a dual-phase of FHA/β-TCP in scaffold was confirmed. The uniform morphology in scaffolds and the pore size distribution of large pores (100-400 µm) containing small ones (10~50 µm) were demonstrated by SEM images. HA and β-TCP were also used to prove the universality of this method. Furthermore, the pore formation and its mechanism were discussed in detail.