Superparamagnetic iron oxide nanoparticles as a liver MRI contrast agent: contribution of microencapsulation to improved biodistribution.
We have developed a new method of synthetizing superparamagnetic iron oxide nanoparticles, consisting in the modifications of Molday's method, which ensures high relaxivity (2.4 10(5) s-1.M-1.L), good chemical stability, singular biodistribution and a considerable safety margin. The ED (Efficace Dose) to LD50 ratio is 1/2400 instead of 1/50 for Gd-DTPA. In order to develop a magnetite-delivery system to the liver we have incorporated the nanoparticles into biodegradable synthetic microcapsules. Encapsulated 59Fe oxide nanoparticles are injected into rats; in these conditions the sequestration is 9-fold greater in liver and 6 and 5 times lower in blood and carcase, respectively. This modification of the biodistribution enables the use of magnetite containing microcapsules at only 0.3 mg/kg iron to obtain an improved contrast in liver.
Pouliquen
D
D
Laboratoire de Biophysique, Faculté de Médecine, Angers, France.
Perdrisot
R
R
Ermias
A
A
Akoka
S
S
Jallet
P
P
Le Jeune
J J
JJ
D000818:Animals; D002214:Capsules; D003287:Contrast Media / Q000008:administration & dosage*; D004339:Drug Compounding; D007501:Iron / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008099:Liver / Q000033:anatomy & histology* / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010087:Oxides / Q000008:administration & dosage / Q000493:pharmacokinetics*; D010316:Particle Size; D051381:Rats; D011919:Rats, Inbred Strains; D014018:Tissue Distribution
D002214:Capsules; D003287:Contrast Media; D010087:Oxides; D007501:Iron