交联聚天冬氨酸基聚离子胶束的制备与表征

Preparation and Characterization of Cross-linked Polyion Micelles Formed by Polyaspartic Acid Derivates

通过胺端基聚乙二醇(CH3O-PEG-NH2)开环聚琥珀酰亚胺(PSI),进一步碱解和胺解制备了聚乙二醇接枝聚天冬氨酸(PEG-g-PAsp)和聚乙二醇接枝聚乙二胺基天冬酰胺(PEG-g-PDEA)两种聚天冬氨酸衍生物.利用它们之间的静电相互作用,在磷酸缓冲液中形成了以PEG为壳、聚天冬氨酸复合物为核的聚离子胶束.研究发现,该聚离子胶束粒子呈球形,粒径约为70nm,且粒径分布较窄.然而,体系的稳定性受溶液的pH和盐离子强度影响较大.通过戊二醛交联PEG-g-PDEA中的伯胺可以有效提高该聚离子胶束对pH和盐离子强度的稳定性.

Two kinds of polyaspartic acid （PAsp） derivates, i.e. PEG-g-PAsp and PEG-g-PDEA, were prepared through the ring-opening reaction of polysuccinimide by CHaO-PEG-NH2, followed by alkaline hydrolysis and aminolysis, respectively. Utilizing the electrostatic interaction between them, polyion micelles with PEG shell and PAsp complex core were formed in phosphate buffer. The results showed that the polyion micelles are spherical with an average diameter of about 70 nm, and the size distribution is narrow. However, the stability of polyion micelles was strongly affected by pH and ionic strength. Crosslinking of primary amine contained in PEG-g-PDEA by glutaric dialdehyde could effectively improve the stability of polyion micelles to pH and ionic strength.