Xu Qingguo, Czernuszka Jan T
Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, United Kingdom.
J Control Release. 2008 Apr 21;127(2):146-53. doi: 10.1016/j.jconrel.2008.01.017. Epub 2008 Feb 11.
Negatively charged poly(lactic-co-glycolic acid) (PLGA) microspheres with an encapsulated hydrophilic antibiotic (amoxicillin) have been prepared by the solid-in-oil-in-water (s/o/w) method using the anionic surfactant, sodium dodecyl sulfate (SDS). Drug encapsulation efficiency is over 40%. Successful coating of hydroxyapatite (HA) on these negatively charged PLGA microspheres has been achieved by a dual constant composition method in 3-6 h. The HA-coated PLGA microspheres (HPLG) have been characterised by zeta-potential and particle size measurements and the coating has been confirmed to be calcium deficient HA by analysis of X-ray diffraction, Fourier transform infrared spectroscopy and wavelength dispersive spectroscopy. The morphology of HPLG was studied by scanning electron microscopy, and cross sections of HPLG microspheres were prepared and imaged using focused ion beam microscopy. In-vitro drug release experiments in PBS (pH7.4) showed a sustained release profile for at least 31 days with little initial burst release. It shows a triphasic drug release profile commonly observed for biodegradable polymers.
使用阴离子表面活性剂十二烷基硫酸钠（SDS），通过水包油包固体（s/o/w）法制备了包封有亲水性抗生素（阿莫西林）的带负电荷的聚乳酸-乙醇酸共聚物（PLGA）微球。药物包封效率超过40%。通过双恒组成法在3至6小时内成功地在这些带负电荷的PLGA微球上包覆了羟基磷灰石（HA）。通过zeta电位和粒径测量对HA包覆的PLGA微球（HPLG）进行了表征，并且通过X射线衍射、傅里叶变换红外光谱和波长色散光谱分析证实该涂层为缺钙型HA。通过扫描电子显微镜研究了HPLG的形态，并使用聚焦离子束显微镜制备了HPLG微球的横截面并成像。在PBS（pH7.4）中进行的体外药物释放实验显示出至少31天的持续释放曲线，初始突释很少。它显示出可生物降解聚合物常见的三相药物释放曲线。
