DOTA-tris(acid)-amido-dPEG®₂₄-amido-dPEG®₂₄-DSPE

DOTA-tris(acid)-amido-dPEG®24-amido-dPEG®24-DSPE, product number QBD-11384, is designed incorporation of lanthanide radionuclides into liposomes or micelles for transport and delivery in radiopharmaceutical applications such as radioimaging and radiotherapeutics. The molecule consists of the macrocycle 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) coupled to a long (152 atoms, 180.0 Å) single molecular weight, discrete polyethylene glycol (dPEG®) spacer and terminated with 1,2-Distearoyl-sn-glycero-3-phosphoethanolamine (DSPE). The dPEG® spacer consists of two dPEG®24 linkers joined by an amide bond with the functional groups at either end. Effectively, this is a dPEG®48 spacer with a molecular weight slightly more than 2000 Daltons (PEG2000).

DOTA, a highly popular bifunctional chelator, forms thermodynamically stable, kinetically inert complexes with Ln(III) ions, such as yttrium. Thus, DOTA has become the preferred ligand for targeted radiopharmaceutical applications that use lanthanide isotopes. QBD-11384 can be used in liposomes or micelles to deliver metal radioisotopes to targets of interest in vitro or in vivo for imaging or therapeutic applications. The dPEG® surface coating will reduce or eliminate opsonization. Consequently, more liposomes or micelles will reach the target, leading to higher effectiveness and lower dosing requirements.