Li Haiyan, Chang Jiang
Biomaterials and Tissue Engineering Research Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China.
J Control Release. 2005 Oct 20;107(3):463-73. doi: 10.1016/j.jconrel.2005.05.019.
Composite microspheres have been prepared from bioactive wollastonite (W) and biodegradable poly (hydroxybutyrate-polyhydroxyvalerate) (PHBV) in the present study. Gentamicin was encapsulated into the microspheres by the absorption method and the in vitro release of the gentamicin from the microspheres was performed in distilled water, modified simulated body fluid (SBF) and phosphate buffered saline (PBS) at 37 degrees C for 22 days, respectively. The results showed that the release behavior of gentamicin from PHBV/W composite microspheres was similar to that from the pure PHBV microspheres when the experiment was performed in distilled water. However, in the PBS and SBF solutions, gentamicin released from the PHBV/W composite microspheres at a relatively lower rate as compared to that of the pure PHBV microspheres and 90% of the total amount of gentamicin released from the composite microspheres after soaking for 22 days, which was much longer than that for the release of the same amount gentamicin from the pure PHBV microspheres (8 days). Scanning electron microscopy (SEM) and energy-dispersive spectrometer (EDS) analysis on the microspheres after release in SBF and PBS revealed that a microporous apatite layer was formed on the composite microspheres surface, which resulted in a controlled release behavior of the gentamicin from the PHBV/W composite microspheres. All of these results provided the possibility that the PHBV/W composite microspheres could be applied as alternative drug controlled release systems, especially as bone fillings for bone repair due to their advantages of controlled releasing antibiotics and apatite-formation ability, through which the implanted microspheres could chemically bond to the surrounding tissue in vivo.
在本研究中，已由生物活性硅灰石（W）和可生物降解的聚（羟基丁酸酯-聚羟基戊酸酯）（PHBV）制备了复合微球。通过吸附法将庆大霉素包封到微球中，并分别在37℃下于蒸馏水、改性模拟体液（SBF）和磷酸盐缓冲盐水（PBS）中对庆大霉素从微球中的体外释放进行了22天的研究。结果表明，当在蒸馏水中进行实验时，庆大霉素从PHBV/W复合微球中的释放行为与从纯PHBV微球中的释放行为相似。然而，在PBS和SBF溶液中，与纯PHBV微球相比，庆大霉素从PHBV/W复合微球中的释放速率相对较低，浸泡22天后，复合微球中释放的庆大霉素总量的90%，这比从纯PHBV微球中释放相同量庆大霉素的时间（8天）长得多。对在SBF和PBS中释放后的微球进行扫描电子显微镜（SEM）和能量色散光谱仪（EDS）分析表明，在复合微球表面形成了微孔磷灰石层，这导致了庆大霉素从PHBV/W复合微球中的控释行为。所有这些结果提供了一种可能性，即PHBV/W复合微球可作为替代药物控释系统应用，特别是作为骨修复的骨填充物，因为它们具有控释抗生素和形成磷灰石的能力，通过这种能力，植入的微球可以在体内与周围组织发生化学键合。
