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 language | English |
|---|---|
| Pages (from-to) | 242-250 |
| Number of pages | 9 |
| Journal | Journal of Peptide Science |
| Volume | 15 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2009 |
Fingerprint
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 journal › Article
}
TY - JOUR
T1 - Micelles derivatized with octreotide as potential target-selective contrast agents in MRI
AU - Morisco, Anna
AU - Accardo, Antonella
AU - Gianolio, Eliana
AU - Tesauro, Diego
AU - Benedetti, Ettore
AU - Morelli, Giancarlo
PY - 2009
Y1 - 2009
N2 - 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.
AB - 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.
KW - Fluorescence spectroscopy and circular dichroism
KW - Micelles
KW - MRI contrast agent
KW - Octreotide
UR - http://www.scopus.com/inward/record.url?scp=63449132697&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=63449132697&partnerID=8YFLogxK
U2 - 10.1002/psc.1087
DO - 10.1002/psc.1087
M3 - Article
VL - 15
SP - 242
EP - 250
JO - Journal of Peptide Science
JF - Journal of Peptide Science
SN - 1075-2617
IS - 3
ER -