Octreotide labeled aggregates containing platinum complexes as nanovectors for drug delivery

The synthesis, formulation and a complete physico‐chemical characterization, by dynamic light scattering and small angle neutron scattering techniques, of new liposomal aggregates obtained by co‐assembling an amphiphilic molecule containing a platinum complex, Peg 1500 ‐Lys(Pt‐aminoEtGly)‐Lys(C18) 2 , (abbreviated as (C18) 2 ‐PKAG‐Pt), with a second amphiphilic monomer, (C 18 H 37 ) 2 NCO(CH 2 ) 2 CO(AdOO) 5 ‐Oct ((C18) 2 L 5 ‐Oct), containing the octreotide bioactive peptide, is reported. Liposomes of (C18) 2 ‐PKAG‐Pt present a radius of 48 nm, whereas the mixed aggregates (C18) 2 ‐PKAG‐Pt/(C18) 2 L 5 ‐Oct at 90/10 M ratio give larger liposomes with a radius of 84 nm. In both cases, the bilayer thickness is ~5.3 nm. Encapsulation of doxorubicin in mixed liposomes is also obtained by using the pH gradient method. The obtained liposomes could represent a new target selective cargo system for delivery of cisplatin based drugs and/or doxorubicin on cells overexpressing the sstr2 and sstr5 somatostatin receptors. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.