化学学报 ›› 2012, Vol. 70 ›› Issue (02): 177-182.DOI: 10.6023/A1109081 上一篇    下一篇

研究论文

乙二醇-聚(咪唑丙基-天冬酰胺)-聚丙氨酸三嵌段共聚物的合成及其pH-响应性药物控制释放性能的研究

于树芳a, 顾鑫a, 伍国琳a, 王铮a, 王亦农a, 高辉b, 马建标b   

  1. a 功能高分子材料教育部重点实验室 南开大学高分子化学研究所 天津 300071;
    b 化学化工学院 天津理工大学 天津 300191
  • 投稿日期:2011-09-08 修回日期:2011-11-30 发布日期:2012-02-25
  • 通讯作者: 伍国琳 E-mail:guolinwu@hotmail.com
  • 基金资助:

    天津市自然科学基金(Nos.09JCYBJC03400, 10JCYBJC26800);高等学校博士学科点专项科研基金(No.20090031120012)和中央高校基本科研业务费专项基金资助项目.

Preparation and pH-Sensitive Drug Delivery Study of mPEGpoly(Imidazole Propyl-Asparagine)-poly(L-Alanine)

Yu Shufanga, Gu Xina, Wu Guolina, Wang Zhenga, Wang Yinonga, Gao Huib, Ma Jianbiaob   

  1. a Key Laboratory of Functional Polymer Materials, Institute of Polymer Chemistry, Nankai University, Tianjin 300071;
    b School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin 300191
  • Received:2011-09-08 Revised:2011-11-30 Published:2012-02-25
  • Supported by:

    Project supported by the Natural Science Foundation of Tianjin (Nos.09JCYBJC03400, 10JCYBJC26800);the Ph.D. Programs Foundation for New Teachers of Education Ministry of China (No.20090031120012) and Fundamental Research Funds for the Central Universities.

聚天冬氨酸及其衍生物是一种具有良好生物相容性和可生物降解性的高分子材料, 被广泛应用于生物医药领域. 本研究通过大分子引发剂ω-胺基-α-甲氧基聚乙二醇引发N-羧基-α-氨基环内酸酐开环聚合和N-(3-氨丙基)咪唑侧基改性, 制备了一种侧链含有咪唑丙基的聚乙二醇-聚(咪唑丙基-天冬酰胺)-聚丙氨酸三嵌段共聚物. 在水溶液中, 此聚合物可自组装形成一种核-壳-冠型的三层共聚物胶束, 其中疏水性的聚丙氨酸链段自聚集形成胶束的核, 聚(咪唑丙基-天冬酰胺)链段形成具有pH-响应性的壳层, 用于包埋和释放药物, 外围的聚乙二醇链段可以提供一个稳定的水合冠层, 延长药物的体内循环时间. 利用咪唑环与游离阿霉素之间的π-π相互作用和疏水相互作用可以在自组装的过程中将阿霉素包埋到胶束内. 研究发现, 载药胶束随环境pH 值的降低药物的释放速率显著增加. 这主要是由于咪唑环在酸性条件下的质子化导致链段亲疏水性质发生明显变化.

关键词: 聚天冬氨酸, 咪唑, 阿霉素, pH-响应性, 药物释放

Stimuli-sensitive drug delivery systems have attracted considerable interest in recent years for biomaterials scientists. It is well known that the pH value drops from physiologically 7.4 to that lower than 6.5 in tumor tissues, and such difference can be used as a trigger for drug releasing. Poly(amino acid)s (PAAs) have been studied for decades in the fields of drug delivery system due to their biocompatibility, biodegradability, precise secondary conformation and structural versatility. In this study, a novel biodegradable ABC type triblock copolymer mPEG-poly(benzyl L-aspartate)-poly(L-Alanine) (mPEG-PBLA-PLAla) was synthesized by N-carboxyl anhydride ring-opening polymerization. Imidazole groups were tethered to the side chains of poly(L-Asparagine) segments by aminolysis. It was found that this tri-block copolymer can form nano-scale core-shell-corona trilayer micelles in aqueous solution. The PLAla, Poly(L-Asparagine) and mPEG segments serve as a hydrophobic core, a pH-sensitive shell, and a hydrophilic corona, respectively. An antitumor agent, doxorubicin (DOX), was successfully loaded into the nanocarrier via combined actions of hydrophobic and π-π interaction. The drug release profiles displayed a pH-dependent behavior. DOX release rate increased significantly as the solution pH dropped from the physiological pH to acidic. This is most likely due to protonation and a change in hydrophilicity of the imidazole groups in the poly(L-Asparagine).

Key words: poly(aspartic acid), imidazole, DOX, pH-responsive, drug delivery