CT visualization of blood pool in rats by using long-circulating, iodine-containing micelles.
OBJECTIVE
Small, long-circulating particulate carriers of contrast agents, such as micelles, are potentially useful in computed tomographic (CT) blood-pool imaging. An iodine-containing amphiphilic block-copolymer consisting of iodine-substituted poly-L-lysine (MPEG-iodolysine) forms micelles in an aqueous solution. The biodistribution and CT depiction of these radiopaque micelles were therefore studied in rats.


METHODS
MPEG-iodolysine micelles were synthesized and injected into rats via the tail vein at a dose of 170 mg iodine per kilogram. Three animals were used, and tissue enhancement was followed on serial CT scans.


RESULTS
MPEG-iodolysine block-copolymer forms particulates with an average diameter of 80 nm and an iodine content of 33.8%. After intravenous injection into rats, the agent produced noticeable and sustained enhancement of the blood pool (aorta and heart), liver, and spleen for least 3 hours.


CONCLUSIONS
In rats, MPEG-iodolysine micelles were a long-lived blood-pool contrast agent useful for CT.
Torchilin
V P
VP
Department of Radiology, Massachusetts General Hospital, Charlestown, USA.
Frank-Kamenetsky
M D
MD
Wolf
G L
GL
D000818:Animals; D001027:Aortography; D001769:Blood; D003287:Contrast Media / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D006321:Heart / Q000000981:diagnostic imaging; D007275:Injections, Intravenous; D007668:Kidney / Q000000981:diagnostic imaging; D008099:Liver / Q000000981:diagnostic imaging; D008297:Male; D008823:Micelles; D011092:Polyethylene Glycols / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D011107:Polylysine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000493:pharmacokinetics; D011856:Radiographic Image Enhancement; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000000981:diagnostic imaging; D013997:Time Factors; D014018:Tissue Distribution; D014057:Tomography, X-Ray Computed; D014283:Triiodobenzoic Acids / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics
D003287:Contrast Media; D008823:Micelles; D014283:Triiodobenzoic Acids; C107536:methoxypoly(ethyleneglycol)-poly(epsilon-N-(2,4,6-triiodobenzoyl)lysine) block copolymer; D011107:Polylysine; D011092:Polyethylene Glycols