Development of a novel gene delivery scaffold utilizing colloidal gold-polyethylenimine conjugates for DNA condensation

M. M. Ow Sullivan, J. J. Green, T. M. Przybycien

Research output: Contribution to journalArticlepeer-review


We have developed a novel gene delivery scaffold based on DNA plasmid condensation with colloidal gold/polyethylenimine conjugates. This scaffold system was designed to enable systematic study of the relationships between DNA complex physical properties and transfection efficiency. Using an enhanced green fluorescent protein-coding reporter plasmid and a Chinese hamster ovary cell line, we have measured the transfection efficiencies of our complexes using flow cytometry and their cytotoxicities using the trypan blue assay. We have also assayed complex particle morphologies using atomic force microscopy, photon correlation spectroscopy, and a novel plasmon absorbance peak position analysis. We achieved comparable rates of transfection relative to the commonly used polycationic condensation agents calcium phosphate and LipofectAMINE™, with comparably low cytotoxicities. In addition, by manipulating colloidal gold concentration, we could partially decouple complex physical properties including charge ratio, size, DNA loading, and polyethylenimine concentration. Our morphological analyses showed that complexes with a diameter of a few hundred nanometers and a charge ratio of ∼ 8 perform best in our transfection efficiency assays. The use of colloidal gold as a component in our delivery system provides a versatile system for manipulating complex properties and morphology as well as a convenient scaffold for planned ligand conjugation studies.

Original languageEnglish (US)
Pages (from-to)1882-1890
Number of pages9
JournalGene Therapy
Issue number22
StatePublished - Oct 2003
Externally publishedYes


  • Atomic force microscopy
  • Colloidal gold
  • Flow cytometry
  • Nonviral gene delivery
  • Polyethylenimine (PEI)

ASJC Scopus subject areas

  • Molecular Medicine
  • Molecular Biology
  • Genetics


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