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采用乳化交联法制备出粒径主要分布在100~300μm的载药明胶微球,分析了交联剂含量、药物含量和转速对载药率和包封率的影响及药物含量和转速对微球粒径的影响.对载药明胶微球与磷酸镁基骨水泥进行复合,探讨微球降解过程中复合体系孔隙率的变化及其在体外药物释放的规律,以期获得一种具有药物缓释性能的多孔磷酸镁基复合骨水泥.结果表明,随着葡萄糖浓度增加,载药率和包封率先上升再下降;随着药物含量的增加,载药率保持上升,包封率先上升后下降;随着转速增加,载药率和包封率均下降.综合分析,在转速为400 r/min、葡萄糖浓度为0.5 g/mL、药物与明胶质量比为1:2的条件下制备的载药明胶微球载药量较高,且粒径合适.将复合不同比例该载药微球的磷酸镁基骨水泥浸泡在Tris-HCl缓冲溶液中进行体外药物释放研究,结果表明:在释放前期(0~10 h)药物释放速率较快,之后药物释放明显减缓.7 d后,微球几乎降解完全,药物释放率达到60%~89%,达到了一定的药物缓释效果.

Emulsification crosslinking method was applied to prepare drug-loaded gelatin microspheres, of which the particle size was mainly between 100–300μm. The influence of the crosslinking agent content, drug content and rota-tion speed on the drug-loading rate and encapsulation efficiency and the influence of the drug content and rotation speed on the microspheres' diameter were analyzed. The drug-loaded gelatin microspheres were deliberately combined with magnesium phosphate cement to produce porous magnesium phosphate composite bone cement with drug slow-release property, and then the changes of porosity of the composite system in the process of microsphere degra-dation and the drug release characteristics of the composite systemin vitro were both explored. Results show that with the increase of glucose concentration, both the drug-loading rate and encapsulation efficiency increase firstly and then decrease, while both the drug content and the drug-loading rate increase and the encapsulation efficiency increases firstly and then decreases. Both the drug-loading rate and encapsulation efficiency decrease with the increase of rotation speed. Comprehensive analysis show that the gelatin microspheres with high drug-loading rate and suitable di-ameter can be obtained under the condition of rotation speed of 400 r/min, glucose concentration of 0.5 g/mL and the mass ratio of drug to gelatin of 1:2. The drug release characteristicsin vitro were studied by immersing the magnesium phosphate cement, which was combined with different proportions of drug-loaded microspheres, into the Tris-HCl buffer solution. Results show that in the early releasing stage of 1–10 h, the drug release rate is rapid and then it obvi-ously slows down. After being released for 7 d, microspheres almost degraded completely and the drug release ratio reaches 60%–89%. Drug slow-release property is achieved to some extent.