Journal of the American Chemical Society · 2005 · 142 citations · 20 references
MedicineMedicinal ChemistryPharmacologyBiomaterialsMolecular ImagingTheranosticsBone TissueCalcium Phosphate BiomaterialsCalcium Phosphate MaterialsLigand BindingRadiopharmaceutical DesignSynthetic Bone SubstitutesBone Surface ImagingBone-seeking RadiopharmaceuticalsContrast Agent RelaxivityContrast Agent SynthesisHydroxyapatiteHydroxyapatite-based MaterialsMacrocyclic LigandsRotational Correlation Time
A new macrocyclic DOTA-like ligand (BPAMD) for bone imaging and therapy containing a monoamide bis(phosphonic acid) bone-seeking group was designed and synthesized. Its lanthanide(III) complexes were prepared and characterized by 1H and 31P NMR spectroscopy. The Gd(III)-BPAMD complex was investigated in detail by 1H and 17O relaxometric studies to inspect parameters relevant for its potential application as an MRI contrast agent. Sorption experiments were conducted with Gd(III) and Tb(III) complexes using hydroxyapatite (HA) as a model of bone surface. Very effective uptake of the Gd-BPAMD complex by the HA surface was observed in NMR experiments. Radiochemical studies with the (160Tb-BPAMD)-HA system proved the sorption to be remarkably fast and strong on one hand and fully reversible on the other hand. The strong (Gd-BPAMD)-HA interaction was also supported by 1H NMRD measurements in the presence of a hydroxyapatite slurry, which showed an increase of the rotational correlation time upon adsorption of the complex on the HA surface, resulting in a significant relaxivity enhancement. The amide-bis(phosphonate) moiety is the only factor responsible for the binding of the complex to HA.
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D. Hugh Powell, O.M.N. Dhubhghaill, Dirk Pubanz et al. · Journal of the American Chemical Society · 1996 · 644 citations · Full text