Acta Phys. -Chim. Sin. ›› 2016, Vol. 32 ›› Issue (10): 2628-2635.doi: 10.3866/PKU.WHXB201606296

• ARTICLE • Previous Articles     Next Articles

Preparation of Fluorescently Labeled pH-Sensitive Micelles for Controlled Drug Release

Wei-Ju HAO1,Jun-Qi ZHANG2,Ya-Zhuo SHANG1,Shou-Hong XU1,*(),Hong-Lai LIU1   

  1. 1 State Key Laboratory of Chemical Engineering, Department of Chemistry, East China University of Science and Technology, Shanghai 200237, P. R. China
    2 Department of Medical Microbiology and Parasitology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, P. R. China
  • Received:2016-04-25 Published:2016-09-30
  • Contact: Shou-Hong XU
  • Supported by:
    the National Natural Science Foundation of China(21276074);Fundamental Research Funds for the Centre Universities of China(?)


In this paper, novel pH-sensitive amphiphilic diblock copolymers[mPEG-b-PDPAn (n=100-200, polymerization degree; PEG is polyethylene glycol and PDPA is polydiphenylamine)] with and without a fluorescent group (fluorescein isothiocyanate, FITC) were synthesized by atom transfer radical polymerization (ATRP). The copolymers were used to prepare micelles by solvent evaporation to act as drug carriers. The micelles were spherical with a uniform diameter of 180-240 nm (0.3 mg·mL-1). The model drug doxorubicin (DOX) could be encapsulated into the micelles with a high loading efficiencyof about 11% (w, mass fraction). The micelles were stable at pH 7.4 and became looser upon the protonation of the PDPA block in a weakly acidic environment. The release of DOX accelerated when the micelles were exposed to weakly acidic conditions, and the amount released reached 80%after 2-3 h. Cell toxicity assays of the micelles were carried out using human cancer cells (Huh7), and the micelles showed good cytocompatibility. The micelles labeled with FITC displayed high cell transfection efficiency. As a result, micelles labeled with fluorescent groups may open up new perspectives for real-time tracking of drug delivery and/or distribution during chemotherapy.

Key words: pH-sensitive copolymer, Self-assembly micelle, Targeting delivery, Controlled release