Cellular uptake mechanism of molecular umbrella

Bioconjug Chem. 2009 Dec;20(12):2311-6. doi: 10.1021/bc9003074.

Abstract

Molecular umbrella provided a promising avenue for the design of the intracellular delivery of hydrophilic therapeutic agents. However, the limited understanding of its cellular uptake would be a roadblock to its effective application. Herein, we investigate the ability and mechanism of cellular entry of a fluorescently labeled diwalled molecular umbrella, which was synthesized from cholic acid, spermine, and 5-carboxyfluorescein, into Hela cells, with the extent of uptake analyzed by confocal fluorescence microscopy and flow cytometry. It is found that the as-synthesized diwalled molecular umbrella can greatly facilitate cellular uptake of hydrophilic agent, 5-carboxyfluorescein. In vitro experiments with diffuse marker, endocytic marker, and inhibitors suggested that several distinct uptake pathways (e.g., passive diffuse, clathrin-mediated endocytosis, and caveolae/lipid-raft-dependent endocytosis) are involved in the internalization of diwalled molecular umbrella. These results, together with its low toxicity and good biocompatibility, thus demonstrate the suitability of molecular umbrella for application as vectors in drug delivery systems.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biocompatible Materials / chemistry
  • Biocompatible Materials / metabolism*
  • Biocompatible Materials / pharmacokinetics
  • Biological Transport
  • Cell Membrane / chemistry
  • Cell Membrane / metabolism*
  • Cells, Cultured
  • Cholic Acid / chemistry
  • Cholic Acid / metabolism*
  • Cholic Acid / pharmacokinetics
  • Drug Carriers / chemistry
  • Drug Carriers / metabolism*
  • Drug Carriers / pharmacokinetics
  • Drug Delivery Systems
  • Fluoresceins / chemistry
  • Fluoresceins / metabolism
  • Fluorescent Dyes / chemistry
  • Fluorescent Dyes / metabolism*
  • Fluorescent Dyes / pharmacokinetics
  • HeLa Cells
  • Humans
  • Hydrophobic and Hydrophilic Interactions
  • Lipid Bilayers / chemistry
  • Lipid Bilayers / metabolism
  • Molecular Conformation
  • Spermidine / chemistry
  • Spermidine / metabolism*
  • Spermidine / pharmacokinetics
  • Structure-Activity Relationship

Substances

  • Biocompatible Materials
  • Drug Carriers
  • Fluoresceins
  • Fluorescent Dyes
  • Lipid Bilayers
  • 4-carboxyfluorescein
  • Cholic Acid
  • Spermidine