Preliminary evaluation of a polyethyleneglycol-stabilized manganese-substituted hydroxylapatite as an intravascular contrast agent for MR angiography

Autor: Michael R. Hynes, Debiao Li, Kofi Adzamli, Dennis L. Nosco, Richard B. Dorshow, Max D. Adams
Rok vydání: 1997
Předmět:
Zdroj: Journal of Magnetic Resonance Imaging. 7:204-208
ISSN: 1522-2586
1053-1807
DOI: 10.1002/jmri.1880070131
Popis: A blood-persistent particulate paramagnetic contrast agent has been formulated via size stabilization of manganese-substituted hydroxylapatite by a polyethylene glycol (PEG) bearing a terminal diphosphonate. At high PEG surface densities (35-40 mol%), particles with mean diameter 8 +/- 2 nm were obtained. Relaxivities of autoclaved samples (at 20 MHz proton Lamor frequency) were R1 = 18.7 +/- .8 mM-1 sec-1 and R2 = 22.3 +/- .7 mM-1 sec-1. The formulation persisted in rabbit blood with a biphasic clearance profile. Half-lives (with amplitudes in parenthesis) were 4 +/- 1 minutes (55%), and 49 +/- 3 minutes (45%), respectively, for the two phases. A dose of 40 mumol Mn/kg body weight enhanced the signal from rabbit vasculature for more than 45 minutes on MR angiograms. Thus, PEG-modified MnHA particles may find use as T1 agents for MR angiography.
Databáze: OpenAIRE