Monomer-coated very small superparamagnetic iron oxide particles as contrast medium for magnetic resonance imaging: preclinical in vivo characterization.
OBJECTIVE
Preclinical in-vivo characterization of a newly developed MR contrast medium consisting of very small superparamagnetic iron oxide particles (VSOP) coated with citrate (VSOP-C184).


METHODS
VSOP-C184 (core diameter: 4 nm; total diameter: 8.6 nm; relaxivities in water at 0.94 T (T1) 20.1 and (T2) 37.1 l/[mmol*sec]) was investigated to determine its pharmacokinetics, efficacy, acute single dose toxicity, repeated dose toxicity, and genotoxicity.


RESULTS
The plasma elimination half-life at 0.045 mmol Fe/kg was 21.3 +/- 5.5 minutes in rats and 36.1 +/- 4.2 minutes in pigs, resulting in a T1-relaxation time of plasma of < 100 milliseconds for 30 minutes in pigs. The particles are mainly cleared via the phagocytosing system of the liver. MR angiography at a dose of 0.045 mmol Fe/kg shows an excellent depiction of the thoracic and abdominal vasculature in rats and of the coronary arteries in pigs. The LD50 in mice is > 17.9 mmol Fe/kg. A good tolerance and safety profile was found.


CONCLUSIONS
The experiments indicate, that VSOP-C184 may be a well tolerated and safe contrast medium for MR imaging that can be effectively used for MR angiography including visualization of the coronary arteries.
Wagner
Susanne
S
Department of Radiology, Charité, Medizinische Fakultät der Humboldt-Universität zu Berlin, Berlin, Germany.
Schnorr
Jorg
J
Pilgrimm
Herbert
H
Hamm
Bernd
B
Taupitz
Matthias
M
D000818:Animals; D002951:Citrates / Q000378:metabolism / Q000494:pharmacology; D003287:Contrast Media / Q000378:metabolism / Q000494:pharmacology*; D017023:Coronary Angiography / Q000379:methods; D007501:Iron / Q000378:metabolism / Q000494:pharmacology; D008099:Liver / Q000378:metabolism; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D051379:Mice; D010087:Oxides / Q000378:metabolism / Q000494:pharmacology; D010316:Particle Size; D051381:Rats; D017208:Rats, Wistar; D013552:Swine
D002951:Citrates; D003287:Contrast Media; D010087:Oxides; D007501:Iron