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采用单乳化溶剂挥发法制备了聚己内酯[poly(ε-caprolactone),PCL]/纳米羟基磷灰石(nano-hydroxyapatite,n-HA)复合微球。使用两种具有不同水溶性的模型药物对硝基苯胺(p-nitroaniline)和罗丹明B(Rhodamine B,RhB),研究n-HA在复合微球中的作用。用扫描电子显微镜观察微球的表面形貌。通过紫外–可见光分光光度法计算药物载量和包封率。用共聚焦激光显微镜分析药物在微球中的分布。分别研究了PCL微球和PCL/HA复合微球的体外释放性质。复合微球可以持续释放药物4周以上,在前3d的突释后,其释放曲线符合Higuchi扩散方程。n-HA的加入使较亲水药物RhB在复合微球中分布更均匀,对较疏水药物对硝基苯胺则影响不明显。n-HA减少了载亲水药物的复合微球在前3d的突释,并减缓了其后的释放速率。结果表明:PCL/n-HA复合结构的材料有希望作为一种新的长效药物释放载体应用。
Poly (ε-caprolactone), PCL] / nano-hydroxyapatite (n-HA) microspheres were prepared by single emulsion solvent evaporation method. Two kinds of p-nitroaniline and Rhodamine B (RhB) were used to study the effect of n-HA in composite microspheres. The surface morphology of the microspheres was observed with a scanning electron microscope. Drug loading and encapsulation efficiency were calculated by UV-Vis spectrophotometry. Confocal laser microscopy was used to analyze the drug distribution in the microspheres. The in vitro release properties of PCL microspheres and PCL / HA composite microspheres were studied. The composite microspheres sustained release of drugs for more than 4 weeks. After the first 3 days of burst release, the release curves of the composite microspheres conform to the Higuchi diffusion equation. The addition of n-HA made the distribution of more hydrophilic RhB in the composite microspheres more uniform, but not obvious for the more hydrophobic drug p-nitroaniline. n-HA reduced burst release of the hydromophilic composite microspheres in the first 3 days and slowed down the subsequent release rate. The results show that the material of PCL / n-HA composite structure is promising as a new long-acting drug release carrier.