Novel optical contrast agents containing both DFO and multi-RGD peptides

Yunpeng Ye, Sharon Bloch, Samuel Achilefu

Research output: Chapter in Book/Report/Conference proceedingConference contribution


A series of novel near-infrared fluorescent compounds containing both desferoxamine (DFO) and multi-RGD peptides, i.e. DFO-Cypate-(RGD) n-NH2 (1), were designed and synthesized based on a dicarboxylic acid-containing near-infrared fluorescent carbocyanine (Cypate) scaffold. The trimeric 1 (n=3) showed the strongest cellular internalization into A549 cells in vitro among the four analogs of 1 (n=1, 2, 3, 4), suggesting that such a linear array of three RGD peptide motifs might be optimal for synergistic effects on cellular internalization. The four analogs showed higher internalization than an integrin αvβ3-targeting cyclic RGD peptide analog DFO-cypate-[RGDfK(∼)] (2) after 1h of incubation, indicating that the linear arrays of multi-RGD peptides might be different from the cyclic RGD peptide analog in the internalization kinetics and mechanism of receptor targeting. Confocal microscopy showed that 1 (n=4) could localize at least in part to the mitochondria. Noteworthy, the two compounds 1 (n=2, 3) resulted in a 1.5 to 2 fold increase in fluorescence of the calcium indicator fluo4 after 30 min of incubation. These results suggest the possible effects of these compounds on the cellular function by internalization. Such a type of near-infrared fluorescent cypate analogs containing both DFO and multi-RGD peptides could provide a platform for discovering and developing novel multifunctional optical contrast agents for integrin receptor targeting as well as related tumor imaging and therapy.

Original languageEnglish (US)
Title of host publicationOptics in Health Care and Biomedical Optics III
StatePublished - 2008
Externally publishedYes
EventOptics in Health Care and Biomedical Optics III - Beijing, China
Duration: Nov 12 2007Nov 15 2007

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


ConferenceOptics in Health Care and Biomedical Optics III


  • Cellular internalization
  • Cypate
  • Desferrioxamine (DFO)
  • Integrin receptor
  • Metal binding
  • Multimeric RGD peptide
  • Near-infrared fluorescent probe
  • Optical imaging

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Biomaterials
  • Radiology Nuclear Medicine and imaging


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