磷脂胆碱聚乳酸自组装胶束的结构与性能

Structure and stability of micelles formed by self-assembling of biodegradable phosphorylcholine-containing poly(L-lactide)

用与天然磷脂结构和相对分子质量类似的磷脂胆碱聚乳酸(Phosphorylcholine-containing poly(L-lactide),PLLA-PC)制备自组装胶束,采用透射电镜和激光共聚焦显微镜进行观察。研究结果表明:胶束为外壳亲水内核疏水的实心球;表面张力法测得临界胶束质量浓度(Critical micelle concentration,CMC)为23mg/L,显著低于天然磷脂胆碱质量浓度;当氯化钠质量分数低于0.9%时,CMC无明显变化,表明胶束在生理盐水中较稳定;胶束被稀释时,动态光散射测得胶束粒径和粒径分布均逐渐变小,表明体系是动态体系;在37℃恒温条件下放置15h,胶束数量、粒径和分布均变小,表明胶束可随时间降解;PLLA-PC胶束生物相容性好,可降解,可望成为新型的控释药物载体。

Self-assembled micelles were prepared from phosphorylcholine-containing poly （L-lactide）（PLLA-PC） with similar molecular structure and molecular mass to natural phospholipids. The global structure with hydrophilic shell and hydrophobic core is confirmed by transmission electron microscope （TEM） and confocal laser scanning microscope （CLSM）. The results show that critical micelle concentration （CMC） is detected to be 23 mg/L with surface tension method, which is much lower than that of natural phospholipids. It remains constant while NaCl concentration varies within 0.9% （mass fraction）, indicating the stability of micelles in physiological saline. The results of dynamic light scattering （DLS） show that the diameter and distribution of micelles decrease gradually with dilution, suggesting a dynamic system. Moreover, the number, panicle size and distribution of micelles diminish after 15 d at 37 ℃, indicating that the micelles can degrade over time. With good biocompatibility and biodegradability PLLA-PC micelle might be a novel alternative for controlled drug release.