本文系统研究了两步pH调节B型明胶水溶胶合成磷酸钙纳米晶多孔微球.实验采用了“两步pH调节法”对80℃明胶—磷酸钠水溶胶的pH进行预调节:用酸对水溶胶的pH值从5.6调节到3.0,再用碱调节到4.0,然后向水溶胶中滴加钙盐溶液合成磷酸钙.研究中也按常规的一步pH调节方式用酸将水溶胶的pH值从5.6调节到4.0,然后合成磷酸钙作为对照实验.结果表明,两步pH调节法使得磷酸钙纳米晶发生有序自组装形成多孔性微球,而一步pH调节法则出现纳米晶无序聚集和生长.同时,按上述两步pH调节法还可以制备微量元素锶掺杂的多孔性微球.以上研究结果对于仿生溶液介质pH预调节方法影响磷酸钙纳米晶聚集、生长具有重要启示,同时这种多孔性磷酸钙微球在骨修复、缓释给药、细胞支架以及生物分离等方面都具有潜在应用价值.%A systematic investigation of two-step pH adjustment route to prepare CaP porous microspheres was performed.HCl-NaOH pairs were used to adjust the pH of gelatin-NaH2PO4 hydrosol firstly to 3.0,and then to 4.0 ('two-step').And another control was to directly adjust pH to 4.0 with HCl solution ('one-step').Spherical CaP beads were produced during the 'two-step' pH adjustment,but irregular aggregation of CaP nanocrystals resulted in the 'one-step' pathway.A remarkable amount of strontium could be doped in the CaP (～ 1.7 wt ％) in such two mineralization processes.This study is an important approach to a more comprehensive understanding of the effect of pH adjustment on biomimetic system and CaP mineralization.It is expected that such porous CaP microspheres can be used for a variety of biomedical areas such as reconstructive surgery,drug carriers,cell scaffolds,and bioseparation.
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