Acta Chimica Sinica ›› 2012, Vol. 70 ›› Issue (02): 177-182.DOI: 10.6023/A1109081 Previous Articles     Next Articles

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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
  • 收稿日期:2011-09-08 修回日期:2011-11-30 出版日期:2012-01-28 发布日期:2012-02-25
  • 通讯作者: 伍国琳
  • 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 Online:2012-01-28 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.

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