Dental Materials Department, Faculty of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
Int J Nanomedicine. 2012;7:221-34. doi: 10.2147/IJN.S27709. Epub 2012 Jan 10.
Low drug entrapment efficiency of hydrophilic drugs into poly(lactic-co-glycolic acid) (PLGA) nanoparticles is a major drawback. The objective of this work was to investigate different methods of producing PLGA nanoparticles containing minocycline, a drug suitable for periodontal infections.
Different methods, such as single and double solvent evaporation emulsion, ion pairing, and nanoprecipitation were used to prepare both PLGA and PEGylated PLGA nanoparticles. The resulting nanoparticles were analyzed for their morphology, particle size and size distribution, drug loading and entrapment efficiency, thermal properties, and antibacterial activity.
The nanoparticles prepared in this study were spherical, with an average particle size of 85-424 nm. The entrapment efficiency of the nanoparticles prepared using different methods was as follows: solid/oil/water ion pairing (29.9%) > oil/oil (5.5%) > water/oil/water (4.7%) > modified oil/water (4.1%) > nano precipitation (0.8%). Addition of dextran sulfate as an ion pairing agent, acting as an ionic spacer between PEGylated PLGA and minocycline, decreased the water solubility of minocycline, hence increasing the drug entrapment efficiency. Entrapment efficiency was also increased when low molecular weight PLGA and high molecular weight dextran sulfate was used. Drug release studies performed in phosphate buffer at pH 7.4 indicated slow release of minocycline from 3 days to several weeks. On antibacterial analysis, the minimum inhibitory concentration and minimum bactericidal concentration of nanoparticles was at least two times lower than that of the free drug.
Novel minocycline-PEGylated PLGA nanoparticles prepared by the ion pairing method had the best drug loading and entrapment efficiency compared with other prepared nanoparticles. They also showed higher in vitro antibacterial activity than the free drug.
将亲水性药物包埋到聚乳酸-共-羟基乙酸（PLGA）纳米粒中时，药物的包埋效率较低，这是一个主要的缺点。本研究的目的是研究不同方法制备米诺环素载 PLGA 纳米粒，米诺环素是一种适用于牙周感染的药物。
使用了不同的方法，如单溶剂和双溶剂蒸发乳液、离子对、纳米沉淀法来制备 PLGA 和聚乙二醇化 PLGA 纳米粒。对所得纳米粒的形态、粒径及分布、载药量和包封率、热性能和抗菌活性进行了分析。
本研究制备的纳米粒呈球形，平均粒径为 85-424nm。不同方法制备的纳米粒的包封率如下：固体/油/水离子对（29.9%）>油/油（5.5%）>水/油/水（4.7%）>改良油/水（4.1%）>纳米沉淀（0.8%）。加入硫酸葡聚糖作为离子对试剂，作为聚乙二醇化 PLGA 和米诺环素之间的离子间隔物，降低了米诺环素的水溶性，从而提高了药物的包封率。使用低分子量 PLGA 和高分子量硫酸葡聚糖也提高了包封率。在 pH7.4 的磷酸盐缓冲液中进行的药物释放研究表明，米诺环素从第 3 天到数周缓慢释放。在抗菌分析中，纳米粒的最小抑菌浓度和最小杀菌浓度至少是游离药物的两倍。
与其他制备的纳米粒相比，通过离子对法制备的新型米诺环素-聚乙二醇化 PLGA 纳米粒具有最佳的载药量和包封率。它们的体外抗菌活性也高于游离药物。
Zotero 插件
