Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701, South Korea.
J Control Release. 2010 Oct 1;147(1):45-53. doi: 10.1016/j.jconrel.2010.06.016. Epub 2010 Jun 30.
Bioabsorbable calcium phosphate (CaP) microspheres that can incorporate alendronate (ALD) through an in situ loading process and can control the ALD release rate have been described. ALD loading into CaP microspheres could be accomplished by emulsification (water-in-oil) and a subsequent CaP nucleation/growth process within the water droplets, which was initiated by a urea-mediated solution precipitation technique. ALD-loaded microspheres with a mean size range of 163-195 μm were obtained in a spherical shape. Inductively coupled plasma mass spectroscopy (ICP-MS), spectrophotometric analysis, and thermogravimetric analysis (TGA) showed that the amount of ALD loaded into the microspheres increased when the ALD feed content increased. Energy-dispersive X-ray spectroscopy (EDX) analysis revealed that the in situ loading process enabled the ALD loading throughout the microspheres. X-Ray diffraction (XRD) analysis demonstrated that crystalline hydroxyapatite (HAp) and amorphous CaP phases coexisted within the microspheres. In addition, the increased loading of ALD resulted in a larger proportion of the amorphous CaP phase within the microspheres. The ALD release rate could be controlled depending on the dissolution rate of microspheres, and ALD could be released over a period of 40 days. The evaluation of the biological activity showed that ALD-loaded CaP microspheres directly blocked osteoclast formation by releasing ALD to monocytic precursor cells and effectively inhibiting their differentiation into osteoclasts.
已描述了可通过原位负载过程将阿仑膦酸钠（ALD）掺入的可生物吸收的磷酸钙（CaP）微球，并且可以控制 ALD 的释放速率。可以通过乳化（油包水）和随后在液滴内进行 CaP 成核/生长过程来完成 ALD 载入 CaP 微球，这是通过尿素介导的溶液沉淀技术引发的。获得了平均粒径范围为 163-195μm 的球形 ALD 负载微球。电感耦合等离子体质谱（ICP-MS），分光光度分析和热重分析（TGA）表明，当 ALD 进料含量增加时，负载到微球中的 ALD 量增加。能谱分析（EDX）表明，原位负载过程使 ALD 负载遍及整个微球。X 射线衍射（XRD）分析表明，结晶羟磷灰石（HAp）和非晶 CaP 相共存于微球中。此外，ALD 的负载增加导致微球内非晶 CaP 相的比例更大。ALD 的释放速率可以根据微球的溶解速率来控制，并且可以在 40 天的时间内释放 ALD。生物活性评估表明，ALD 负载的 CaP 微球通过将 ALD 释放到单核细胞前体细胞中来直接阻止破骨细胞的形成，并有效抑制其分化为破骨细胞。
