Self-assembling DNA quadruplex conjugated to MRI contrast agents

Jianfeng Cai, Erik M. Shapiro, Andrew D. Hamilton

Research output: Contribution to journalArticlepeer-review


We report the preparation and magnetic resonance (MR) characterization of new MRI contrast agents based on gadolinium complexes conjugated to a self-assembling DNA quadruplex scaffold. As a single gadolinium-DOTA chelated DNA strand, the r1 molar relaxivity is 6.4 mM-1 s -1 per Gd and increases to 11.7 mM-1 s-1 per Gd upon formation of a DNA quadruplex. Similar results were obtained when a gadolinium-DOTA dendrimer was conjugated to DNA, with the r1 molar relaxivity increasing to 12.9 mM-1 s-1 per Gd upon the formation of DNA quadruplex, compared to that of 6.0 mM-1 s -1 for a single strand of gadolinium-DOTA dendrimer chelate. This yields an r1 molar relaxivity of 154.8 and 46.8 mM-1 s-1 per DNA quadruplex based on DOTA dendrimer or monomer, respectively. Importantly, the DNA quadruplex scaffold is approximately 2.5 nm3 in size, potentially enabling this type of contrast agent to be used for targeted delivery in vivo to detect specific cells or tissues, even behind intact blood vessels.

Original languageEnglish (US)
Pages (from-to)205-208
Number of pages4
JournalBioconjugate Chemistry
Issue number2
StatePublished - Feb 2009

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Biomedical Engineering
  • Pharmacology
  • Pharmaceutical Science
  • Organic Chemistry


Dive into the research topics of 'Self-assembling DNA quadruplex conjugated to MRI contrast agents'. Together they form a unique fingerprint.

Cite this