Indometacin-loaded micelles based on star-shaped PLLA-TPGS copolymers: effect of arm numbers on drug delivery

  • Jun Chen
  • Amin Ding
  • Yifeng Zhou
  • Pengpeng Chen
  • Ying Xu
  • Wangyan NieEmail author
Original Contribution


Star-shaped copolymers based on star-shaped poly (L-lactide) (s-PLLA) and tocopheryl polyethylene glycol 1000 succinate (TPGS) (s-PLLA-TPGS) were synthesized with structural variation on arm numbers in order to investigate the relationship between the arm numbers of s-PLLA-TPGS copolymers and their micelle properties. The structure and Mw of s-PLLA-TPGS were characterized with 1H NMR, GPC, DSC, and XRD. The indometacin(IMC)-loaded s-PLLA-TPGS micelles were obtained by dialysis method. The effects of arm numbers of s-PLLA-TPGS copolymers on surface morphology, particle size, zeta potential, drug loading content (LC), drug encapsulation efficiency (EE), and in vitro drug release behavior of prepared micelles were studied. The results indicated that the average diameters, LC, and EE of IMC-loaded s-PLLA-TPGS micelles gradually increased in the order of 4-arm, 5-arm, and 6-arm s-PLLA-TPGS copolymers. The in vitro release studies showed that the IMC accumulative release can be decreased by increasing the arm numbers of the s-PLLA-TPGS copolymers, and the release profiles of IMC from the s-PLLA-TPGS copolymers followed the Baker-Lonsdale model equation. The results suggest that the arm number regulation of s-PLLA-TPGS copolymers can provide a new strategy for designing drug carriers of high efficiency.

Graphical abstract


Star-shaped copolymers s-PLLA-TPGS Micelles Indometacin Drug release system 


Conflict of interest

The authors declare that they have no conflict of interest.

Funding information

This work was financed by National Natural Science Foundation of China (Grant No.51602001), Anhui Provincial Natural Science Foundation (1608085QE106) and Scientific Research Fund of Anhui Provincial Education Department (KJ2017A030, KJ2018A0038).

Compliance with ethical standards

The work described has not been published previously and not under consideration for publication elsewhere, in whole or in part.

Supplementary material

396_2019_4542_MOESM1_ESM.doc (466 kb)
ESM 1 (DOC 465 kb)


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Jun Chen
    • 1
  • Amin Ding
    • 1
  • Yifeng Zhou
    • 1
  • Pengpeng Chen
    • 1
  • Ying Xu
    • 1
  • Wangyan Nie
    • 1
    Email author
  1. 1.Anhui Province Key Laboratory of Environment-friendly Polymer Materials, College of Chemistry & Chemical EngineeringAnhui UniversityHefeiPeople’s Republic of China

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