PLGA/O-CMC载药纳米粒子的体外释药行为研究

本文以聚乳酸-乙醇酸共聚物(PLGA)和自行制备的O-羧甲基壳聚糖(O-CMC)为原料，以5-氟尿嘧啶(5-FU)为抗癌药物模型，采用自身设计的改良复乳法制备了载药纳米微粒。微粒平均粒径为98.5nm，粒径分布指数为0.192，粒子表面∈电位为61．48eV，载药率高达18．9％，包封率为86％。然后用SEM动态监测载药纳米粒子降解过程中表面形貌的变化，并连续追踪粒子降解过程中的质量损失和降解介质的pH变化。载药纳米粒子在PBS中的释药行为研究表明：(1)前12h的释药动力学符合Huguchi方程，具有一级释放特性；(2)在20天内的释药动力学符合零级释放特性。

The Degradation and Release Behavior of 5-Fluorouracil-loaded PLGA/O-CMC Nanoparticles in vitro

Due to the attractive biodegradation and physicochemical properties, poly(D,L-lactide-co-glycolic acid) (PLGA)and o-carboxymethyl chitosan(O-CMC) were chosen to microencapsulate 5-fluorouracil(5-FU) by improved W/O/W method.The mean size of the resulting 5-FU-loaded nanoparticles (NPs) was 98.5nm with fine polydispersity(0.192) and high Zeta potential(61.48eV).The drug-loading level and encapsulation efficiency of the NPs were 18.9% and 86%, respectively. SEM was used to study the morphological change of NPs during the degradation;and the weight loss of NPs and pH change of degradation medium were traced as well.The investigation of 5-FU release behavior from NPs showed that(1) the release kinetics of 5-FU from NPs in early 12 hours was coincided with Hugucbi release equation;(2)the release kinetics in 20 days was coincided with Zero-level release.