Polyphenolic Polymersomes of Temperature-Sensitive Poly(N-vinylcaprolactam)-block-Poly(N-vinylpyrrolidone) for Anticancer Therapy

Academic Article

Abstract

  • © 2017 American Chemical Society. We report a versatile synthesis for polyphenolic polymersomes of controlled submicron (<500 nm) size for intracellular delivery of high and low molecular weight compounds. The nanoparticles are synthesized by stabilizing the vesicular morphology of thermally responsive poly(N-vinylcaprolactam)n-b-poly(N-vinylpyrrolidone)m (PVCLn-PVPONm) diblock copolymers with tannic acid (TA), a hydrolyzable polyphenol, via hydrogen bonding at a temperature above the copolymer's lower critical solution temperature (LCST). The PVCL179-PVPONm diblock copolymers are produced by controlled reversible addition-fragmentation chain transfer (RAFT) polymerization of PVPON using PVCL as a macro-chain transfer agent. The size of the TA-locked (PVCL179-PVPONm) polymersomes at room temperature and upon temperature variations are controlled by the PVPON chain length and TA:PVPON molar unit ratio. The particle diameter decreases from 1000 to 950, 770, and 250 nm with increasing PVPON chain length (m = 107, 166, 205, 234), and it further decreases to 710, 460, 290, and 190 nm, respectively, upon hydrogen bonding with TA at 50 °C. Lowering the solution temperature to 25 °C results in a slight size increase for vesicles with longer PVPON. We also show that TA-locked polymersomes can encapsulate and store the anticancer drug doxorubicin (DOX) and higher molecular weight fluorescein isothiocyanate (FITC)-dextran in a physiologically relevant pH and temperature range. Encapsulated DOX is released in the nuclei of human alveolar adenocarcinoma tumor cells after 6 h incubation via biodegradation of the TA shell with the cytotoxicity of DOX-loaded polymersomes being concentration-dependent. Our approach offers biocompatible and intracellular degradable nanovesicles of controllable size for delivery of a variety of encapsulated materials. Considering the particle monodispersity, high loading capacity, and a facile two-step aqueous assembly based on the reversible temperature-responsiveness of PVCL, these polymeric vesicles have significant potential as novel drug nanocarriers and provide a new perspective for fundamental studies on thermo-triggered polymer assemblies in solutions.
  • Published In

  • Biomacromolecules  Journal
  • Digital Object Identifier (doi)

    Author List

  • Kozlovskaya V; Liu F; Xue B; Ahmad F; Alford A; Saeed M; Kharlampieva E
  • Start Page

  • 2552
  • End Page

  • 2563
  • Volume

  • 18
  • Issue

  • 8