Cell labeling via membrane-anchored lipophilic MR contrast agents

Bioconjug Chem. 2014 May 21;25(5):945-54. doi: 10.1021/bc500083t. Epub 2014 May 9.

Abstract

Cell tracking in vivo with MR imaging requires the development of contrast agents with increased sensitivity that effectively label and are retained by cells. Most clinically approved Gd(III)-based contrast agents require high incubation concentrations and prolonged incubation times for cellular internalization. Strategies to increase contrast agent permeability have included conjugating Gd(III) complexes to cell penetrating peptides, nanoparticles, and small molecules which have greatly improved cell labeling but have not resulted in improved cellular retention. To overcome these challenges, we have synthesized a series of lipophilic Gd(III)-based MR contrast agents that label cell membranes in vitro. Two of the agents were synthesized with a multiplexing strategy to contain three Gd(III) chelates (1 and 2) while the third contains a single Gd(III) chelate (3). These new agents exhibit significantly enhanced labeling and retention in HeLa and MDA-MB-231-mcherry cells compared to agents that are internalized by cells (4 and Prohance).

Publication types

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

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Cell Membrane / chemistry*
  • Cell Proliferation
  • Contrast Media / chemistry*
  • Gadolinium / chemistry*
  • HeLa Cells
  • Humans
  • Hydrophobic and Hydrophilic Interactions
  • Magnetic Resonance Imaging*
  • Mice
  • Models, Molecular
  • Molecular Structure
  • NIH 3T3 Cells
  • Organometallic Compounds / chemical synthesis
  • Organometallic Compounds / chemistry*
  • Particle Size
  • Surface Properties

Substances

  • Contrast Media
  • Organometallic Compounds
  • Gadolinium