Micelles based on methoxy poly(ethylene glycol)-cholesterol conjugate for controlled and targeted drug delivery of a poorly water soluble drug

J Biomed Nanotechnol. 2012 Oct;8(5):809-17. doi: 10.1166/jbn.2012.1433.

Abstract

In this study, quercetin (QC) with cancer chemoprevention effect and anticancer potential was loaded into polymeric micelles of methoxy poly(ethylene glycol)-cholesterol conjugate (mPEG-Chol) in order to increase its water solubility. MPEG-Chol with lower critical micelle concentration (CMC) value (4.0 x 10(-7) M - 13 x 10(-7) M) was firstly synthesized involving two steps of chemical modification on cholesterol by esterification, and then QC was incorporated into mPEG-Chol micelles by self-assembly method. After the process parameters were optimized, QC-loaded micelles had higher drug loading (3.66%) and entrapment efficiency (93.51%) and nano-sized diameter (116 nm). DSC analysis demonstrated that QC had been incorporated non-covalently into the micelles and existed as an amorphous state or a solid solution in the polymeric matrix. The freeze-dried formulation with addition of 1% (w/v) mannitol as cryoprotectant was successfully developed for the long-term storage of QC-loaded micelles. Compared to free QC, QC-loaded micelles could release QC more slowly. Moreover, the release of QC from micelles was slightly faster in PBS at pH 5 than that in PBS at pH 7.4, which implied that QC-loaded micelles might be pH-sensitive and thereby selectively deliver QC to tumor tissue with unwanted side effects. Therefore, mPEG-Chol was a promising micellar vector for the controlled and targeted drug delivery of QC to tumor and QC-loaded micelles were also worth being further investigated as a potential formulation for cancer chemoprevention and treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cholesterol / chemistry*
  • Delayed-Action Preparations / chemistry*
  • Diffusion
  • Drug Compounding / methods
  • Micelles
  • Pharmaceutical Preparations / chemistry*
  • Polyethylene Glycols / chemistry*
  • Solubility
  • Suspensions
  • Water / chemistry*

Substances

  • Delayed-Action Preparations
  • Micelles
  • Pharmaceutical Preparations
  • Suspensions
  • Water
  • Polyethylene Glycols
  • monomethoxypolyethylene glycol
  • Cholesterol