Micelles derivatized with octreotide as potential target-selective contrast agents in MRI

Anna Morisco, Antonella Accardo, Eliana Gianolio, Diego Tesauro, Ettore Benedetti, Giancarlo Morelli

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

New amphiphilic monomers (OCA-DTPAGlu and OCA-DOTA) containing, in the same molecule, three different functions: (i) the chelating agent (DTPAGlu or DOTA) able to coordinate gadolinium ion, (ii) the octreotide bioactive peptide able to target somatostatin receptors, and (iii) a hydrophobic moiety with two 18-carbon atoms alkyl chains have been designed and synthesized by solid-phase methods. The novel amphiphilic monomers aggregate, in water solution, giving stable micelles at very low concentration (cmc values of 2.3 × 10-6 mol kg-1 and 2.5 × 10-6 mol kg-1 for OCA-DTPAGlu and OCA-DOTA, respectively) as confirmed by fluorescence spectroscopy. Fluorescence studies and circular dichroism experiments indicate, for the two compounds as well as for their gadolinium complexes (OCA-DOTA(Gd) and OCA-DTPAGlu(Gd)), the complete exposure of octreotide on the micelle surface, and the predominant presence of an antiparallel β-sheet peptide conformation characterized by a β-like turn. The high relaxivity value (r1p = 13.9mM-1 s-1 at 20 MHz and 25 °C), measured for micelles obtained by the gadolinium complex OCA-DTPAGlu(Gd), indicates these aggregates as promising target-selective magnetic resonance imaging (MRI) contrast agents.

Original languageEnglish
Pages (from-to)242-250
Number of pages9
JournalJournal of Peptide Science
Volume15
Issue number3
DOIs
Publication statusPublished - 2009

Fingerprint

Octreotide
Gadolinium
Micelles
Magnetic resonance
Contrast Media
Magnetic Resonance Imaging
Imaging techniques
Monomers
Somatostatin Receptors
Peptides
Fluorescence Spectrometry
Fluorescence spectroscopy
Chelating Agents
Circular Dichroism
Conformations
Carbon
Fluorescence
Ions
Atoms
Molecules

Keywords

  • Fluorescence spectroscopy and circular dichroism
  • Micelles
  • MRI contrast agent
  • Octreotide

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Molecular Medicine
  • Structural Biology
  • Organic Chemistry
  • Drug Discovery
  • Pharmacology

Cite this

Micelles derivatized with octreotide as potential target-selective contrast agents in MRI. / Morisco, Anna; Accardo, Antonella; Gianolio, Eliana; Tesauro, Diego; Benedetti, Ettore; Morelli, Giancarlo.

In: Journal of Peptide Science, Vol. 15, No. 3, 2009, p. 242-250.

Research output: Contribution to journalArticle

Morisco, A, Accardo, A, Gianolio, E, Tesauro, D, Benedetti, E & Morelli, G 2009, 'Micelles derivatized with octreotide as potential target-selective contrast agents in MRI', Journal of Peptide Science, vol. 15, no. 3, pp. 242-250. https://doi.org/10.1002/psc.1087
Morisco, Anna ; Accardo, Antonella ; Gianolio, Eliana ; Tesauro, Diego ; Benedetti, Ettore ; Morelli, Giancarlo. / Micelles derivatized with octreotide as potential target-selective contrast agents in MRI. In: Journal of Peptide Science. 2009 ; Vol. 15, No. 3. pp. 242-250.
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