TY  - JOUR
AU  - Accardo, A.
AU  - Morisco, A.
AU  - Gianolio, E.
AU  - Tesauro, D.
AU  - Mangiapia, G.
AU  - Radulescu, A.
AU  - Brandt, A.
AU  - Morelli, G.
TI  - Nanoparticles containing octeotride peptides and gadolinium complexes for MRI applications
JO  - Journal of peptide science
VL  - 17
SN  - 1075-2617
CY  - New York, NY [u.a.]
PB  - Wiley
M1  - PreJuSER-14184
SP  - 154 - 162
PY  - 2011
N1  - Record converted from VDB: 12.11.2012
AB  - New mixed nanoparticles were obtained by self-aggregation of two amphiplic monomers. The first monomer (C18)(2) L5-Oct contains two C18 hydrophobic moieties bound to the N-terminus of the cyclic peptide octreotide, and spaced from the bioactive peptide by five units of dioxoethylene linkers. The second monomer, (C18)(2) DTPAGlu, (C18)(2) DTPA or (C18)(2) DOTA, and the corresponding Gd(III) complexes, contains two C18 hydrophobic moieties bound through a lysine residue to different polyamino-polycarboxy ligands: DTPAGlu, DTPA or DOTA. Mixed aggregates have been obtained and structurally characterized by small angle neutron scattering (SANS) techniques and for their relaxometric behavior. According to a decrease of negative charges in the surfactant head-group, a total or a partial micelle-to-vesicle transition is observed by passing from (C18)(2) DTPAGlu to (C18)(2) DOTA. The thicknesses of the bilayers are substantially constant, around 50 Å, in the analyzed systems. Moreover, the mixed aggregates, in which a small amount of amphiphilic octreotide monomer (C18)(2) L5-Oct (10% mol/mol) was inserted, do not differ significantly from the respective self-assembled systems. Fluorescence emission of tryptophan residue at 340 nm indicates low mobility of water molecules at the peptide surface. The proton relaxivity of mixed aggregates based on (C18)(2) DTPAGlu(Gd), (C18)(2) DTPA(Gd) and (C18)(2) DOTA(Gd) resulted to be 17.6, 15.2 and 10.0 mM(-1) s(-1) (at 20 MHz and 298K), respectively. The decrease in the relaxivity values can be ascribed to the increase in τ(M) (81, 205 and 750 ns). The presence of amphiphilic octreotide monomer exposed on mixed aggregate surface gives the entire nanoparticles a potential binding selectivity toward somatostatin sstr2 receptor subtype, and these systems could act as MRI target-specific contrast agent.
KW  - Contrast Media: chemistry
KW  - Gadolinium: chemistry
KW  - Magnetic Resonance Imaging: methods
KW  - Nanoparticles: chemistry
KW  - Octreotide: chemistry
KW  - Contrast Media (NLM Chemicals)
KW  - Gadolinium (NLM Chemicals)
KW  - Octreotide (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:21234988
UR  - <Go to ISI:>//WOS:000287164000013
DO  - DOI:10.1002/psc.1308
UR  - https://juser.fz-juelich.de/record/14184
ER  -