Fmoc-conjugated PEG-vitamin E2 micelles for tumor-targeted delivery of paclitaxel: enhanced drug-carrier interaction and loading capacity

AAPS J. 2014 Nov;16(6):1282-91. doi: 10.1208/s12248-014-9651-2. Epub 2014 Sep 6.

Abstract

The purpose of this study is to develop an improved drug delivery system for enhanced paclitaxel (PTX) loading capacity and formulation stability based on PEG5K-(vitamin E)2 (PEG5K-VE2) system. PEG5K-(fluorenylmethoxycarbonyl)-(vitamin E)2 (PEG5K-FVE2) was synthesized using lysine as the scaffold. PTX-loaded PEG5K-FVE2 micelles were prepared and characterized. Fluorescence intensity of Fmoc in the micelles was measured as an indicator of drug-carrier interaction. Cytotoxicity of the micelle formulations was tested on various tumor cell lines. The therapeutic efficacy and toxicity of PTX-loaded micelles were investigated using a syngeneic mouse model of breast cancer (4T1.2). Our data suggest that the PEG5K-FVE2 micelles have a low CMC value of 4 μg/mL and small sizes (~60 nm). The PTX loading capacity of PEG5K-FVE2 micelles was much higher than that of PEG5K-VE2 micelles. The Fmoc/PTX physical interaction was clearly demonstrated by a fluorescence quenching assay. PTX-loaded PEG5K-FVE2 micelles exerted more potent cytotoxicity than free PTX or Taxol formulation in vitro. Finally, intravenous injection of PTX-loaded PEG5K-FVE2 micelles showed superior anticancer activity compared with PEG5K-VE2 formulation with minimal toxicity in a mouse model of breast cancer. In summary, incorporation of a drug-interactive motif (Fmoc) into PEG5K-VE2 micelles represents an effective strategy to improve the micelle formulation for the delivery of PTX.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Antineoplastic Agents, Phytogenic / administration & dosage*
  • Antineoplastic Agents, Phytogenic / pharmacokinetics
  • Antineoplastic Agents, Phytogenic / pharmacology
  • Antineoplastic Agents, Phytogenic / therapeutic use
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Drug Carriers / chemical synthesis
  • Drug Carriers / chemistry*
  • Drug Compounding
  • Drug Stability
  • Female
  • Humans
  • Mammary Neoplasms, Experimental / drug therapy
  • Mammary Neoplasms, Experimental / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Micelles
  • Molecular Targeted Therapy
  • Neoplasm Transplantation
  • Paclitaxel / administration & dosage*
  • Paclitaxel / pharmacokinetics
  • Paclitaxel / pharmacology
  • Paclitaxel / therapeutic use
  • Particle Size
  • Polyethylene Glycols / chemical synthesis
  • Polyethylene Glycols / chemistry*
  • Rats, Sprague-Dawley
  • Tissue Distribution
  • Vitamin E / analogs & derivatives*
  • Vitamin E / chemical synthesis
  • Vitamin E / chemistry

Substances

  • Antineoplastic Agents, Phytogenic
  • Drug Carriers
  • Micelles
  • Vitamin E
  • Polyethylene Glycols
  • Paclitaxel