BLOCK-COPOLYMER OF POLYETHYLENE-GLYCOL AND POLYLYSINE AS A CARRIER OFORGANIC IODINE - DESIGN OF LONG-CIRCULATING PARTICULATE CONTRAST-MEDIUM FOR X-RAY COMPUTED-TOMOGRAPHY
Vs. Trubetskoy et al., BLOCK-COPOLYMER OF POLYETHYLENE-GLYCOL AND POLYLYSINE AS A CARRIER OFORGANIC IODINE - DESIGN OF LONG-CIRCULATING PARTICULATE CONTRAST-MEDIUM FOR X-RAY COMPUTED-TOMOGRAPHY, Journal of drug targeting., 4(6), 1997, pp. 381-388
In order to obtain small, polymer-stabilized particulate carriers for
organic iodine to serve as a contrast agent for X-ray computed tomogra
phy (CT) an attempt was made to design a carrier based on polymeric mi
celles. Here we describe the synthesis of an iodine-containing amphiph
ilic block-copolymer which. can micellize in aqueous solutions. The tw
o blocks of the copolymer consisted of methoxypoly(ethyleneglycol) and
poly[epsilon N-(triiodobenzoyl)-L-lysine]. Upon dispersion in water,
the:block copolymer formed particles with average diameter 80 nm and i
odine content up to 44.7%. The particles start to dissociate to the in
dividual polymeric chains in the concentration range of 0.85-0.5 mu M
in water at 23 degrees C. Upon intravenous injection at 250 mg of iodi
ne/kg (570 mg of the agent/kg) in rabbits the medium demonstrated exce
ptional 24 hr half-life in the blood substantiating corona/core struct
ure of the particles with PEG chains protecting the iodine-containing
core. The possible use of these particulates as contrast medium for X-
ray computed tomography is discussed.