Synthesis of 2-hydroxypropyl-β-cyclodextrin/pluronic-based polyrotaxanes via heterogeneous reaction as potential Niemann-Pick type C therapeutics

Biomacromolecules. 2013 Dec 9;14(12):4189-97. doi: 10.1021/bm400922a. Epub 2013 Nov 1.

Abstract

Five polyrotaxanes were synthesized by threading 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) onto a variety of α,ω-ditriethylenediamino-N-carbamoyl-poly-(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (Pluronic) triblock copolymers using a two-pot strategy under heterogeneous, nonaqueous conditions. The threaded HP-β-CD units were retained on the pseudopolyrotaxane precursors by end-capping the branched diamine termini with sodium 2,4,6-trinitrobenzene sulfonate. Inclusion of the Pluronic copolymers within the HP-β-CD cavities was more favorable in nonpolar solvents, such as diethyl ether and n-hexane, both of which gave better coverage ratios than polar solvents. (1)H NMR and MALDI-TOF were used to estimate the average molecular weights of the purified polyrotaxane products. A globular morphology of aggregated polyrotaxanes was observed by tapping-mode AFM imaging of dried samples. Treatment of Niemann-Pick C (NPC) type 2-deficient fibroblasts with the polyrotaxane derivatives produced substantial reductions in sterol accumulation, as seen by diminished filipin staining in these cells, suggesting that Pluronic-based polyrotaxanes may be promising vehicles for delivery of HP-β-CD to cells with abnormal cholesterol accumulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 2-Hydroxypropyl-beta-cyclodextrin
  • Cells, Cultured
  • Cholesterol / metabolism
  • Cyclodextrins / chemistry
  • Cyclodextrins / metabolism
  • Drug Carriers / chemical synthesis
  • Drug Carriers / metabolism
  • Drug Carriers / pharmacology*
  • Endocytosis
  • Fibroblasts / drug effects
  • Fibroblasts / metabolism
  • Filipin / metabolism
  • Humans
  • Molecular Weight
  • Niemann-Pick Disease, Type C / drug therapy*
  • Poloxamer / chemistry
  • Poloxamer / metabolism
  • Rotaxanes / chemistry
  • Rotaxanes / metabolism
  • beta-Cyclodextrins / chemistry
  • beta-Cyclodextrins / metabolism
  • beta-Cyclodextrins / pharmacology*

Substances

  • Cyclodextrins
  • Drug Carriers
  • Rotaxanes
  • beta-Cyclodextrins
  • polyrotaxane
  • Poloxamer
  • 2-Hydroxypropyl-beta-cyclodextrin
  • Filipin
  • Cholesterol