Lee Jaeyoung, Cho Eun Chul, Cho Kilwon
Department of Chemical Engineering, School of Environmental Engineering, Pohang University of Science and Technology, 790-784 Pohang, South Korea.
J Control Release. 2004 Feb 10;94(2-3):323-35. doi: 10.1016/j.jconrel.2003.10.012.
The poly(ethylene oxide)-poly(lactide) (PEO-PLA) block copolymers containing a small quantity of carboxylic acid in the PLA block were synthesized. The microscopic characteristics of nanoparticles with carboxylic acid content in the copolymer were analyzed, and the effect of specific interactions between the copolymer and the model drug on the drug loading capacity and the release behavior were investigated systematically. The sizes of nanoparticles prepared by a dialysis method are within the range of 30-40 nm. The nanoparticles prepared from functionalized block copolymers have a very low critical micelle concentration (CMC) value as low as approximately 10(-3) mg/ml, which indicates a good stability of the nanoparticles in spite of the presence of carboxylic acid. The drug loading efficiency of nanoparticles dramatically increased when carboxylic acid content was increased in the block copolymer. This result may be attributed to the increase of interactions between the copolymer and the drug. The release rate of the drug was much slower from nanoparticles containing higher amounts of carboxylic acid in the copolymer, which might be associated with the enhanced interaction between the carboxylic group of copolymers and the drug. These experimental results suggest that the nanoparticles prepared from functionalized PEO-PLA block copolymers could be a good candidate for an injectable drug delivery carrier.
合成了在聚丙交酯（PLA）嵌段中含有少量羧酸的聚环氧乙烷-聚丙交酯（PEO-PLA）嵌段共聚物。分析了共聚物中羧酸含量对纳米颗粒微观特征的影响，并系统研究了共聚物与模型药物之间的特定相互作用对载药量和释放行为的影响。通过透析法制备的纳米颗粒尺寸在30 - 40 nm范围内。由功能化嵌段共聚物制备的纳米颗粒具有非常低的临界胶束浓度（CMC）值，低至约10^(-3) mg/ml，这表明尽管存在羧酸，纳米颗粒仍具有良好的稳定性。当嵌段共聚物中羧酸含量增加时，纳米颗粒的载药效率显著提高。这一结果可能归因于共聚物与药物之间相互作用的增强。共聚物中羧酸含量较高的纳米颗粒的药物释放速率要慢得多，这可能与共聚物羧基与药物之间增强的相互作用有关。这些实验结果表明，由功能化PEO-PLA嵌段共聚物制备的纳米颗粒可能是一种良好的可注射药物递送载体候选物。
