Design and in Vitro Validation of Multivalent Dendrimer Methotrexates as a Folate-Targeting Anticancer Therapeutic

Curr Pharm Des. 2013;19(37):6594-605. doi: 10.2174/1381612811319370004.


Design of cancer-targeting nanotherapeutics relies on a pair of two functionally orthogonal molecules, one serving as a cancer cell-specific targeting ligand, and the other as a therapeutic cytotoxic agent. The present study investigates the validity of an alternative simplified strategy where a dual-acting molecule which bears both targeting and cytotoxic activity is conjugated to the nanoparticle as cancer-targeting nanotherapeutics. Herein, we demonstrate that methotrexate is applicable for this dual-acting strategy due to its reasonable affinity to folic acid receptor (FAR) as a tumor biomarker, and cytotoxic inhibitory activity of cytosolic dihydrofolate reductase. This article describes design of new methotrexate-conjugated poly(amidoamine) (PAMAM) dendrimers, each carrying multiple copies of methotrexate attached through a stable amide linker. We evaluated their dual biological activities by performing surface plasmon resonance spectroscopy, a cell-free enzyme assay and cell-based experiments in FAR-overexpressing cells. This study identifies the combination of an optimal linker framework and multivalency as the two key design elements that contribute to achieving potent dual activity.

Publication types

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

MeSH terms

  • Animals
  • Biocompatible Materials / chemistry
  • Biocompatible Materials / pharmacology*
  • Cattle
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Cells, Cultured
  • Dendrimers / chemistry
  • Dendrimers / pharmacology*
  • Drug Delivery Systems
  • Drug Design*
  • Folate Receptor 1 / metabolism
  • Folic Acid / chemistry*
  • Folic Acid Antagonists / pharmacology*
  • Humans
  • In Vitro Techniques
  • Keratinocytes / cytology
  • Keratinocytes / drug effects
  • Macrophages / cytology
  • Macrophages / drug effects
  • Melanoma, Experimental / drug therapy*
  • Melanoma, Experimental / pathology
  • Methotrexate / chemistry
  • Methotrexate / pharmacology*
  • Mice
  • Molecular Targeted Therapy
  • Nanoparticles
  • Surface Plasmon Resonance
  • Validation Studies as Topic


  • Biocompatible Materials
  • Dendrimers
  • Folate Receptor 1
  • Folic Acid Antagonists
  • PAMAM Starburst
  • Folic Acid
  • Methotrexate