Rw. Storrs et al., PARAMAGNETIC POLYMERIZED LIPOSOMES AS NEW RECIRCULATING MR CONTRAST AGENTS, Journal of magnetic resonance imaging, 5(6), 1995, pp. 719-724
We describe a well-tolerated blood pool contrast agent with extended r
ecirculatory half-life based on paramagnetic polymerized liposomes (PP
Ls), PPLs were constructed from a new type of polymerizable lipid mole
cule that has a derivative of gadopentetate dimeglumine as the hydroph
ilic head group and diacetylene groups in the hydrophobic acyl chains,
which cross-link when irradiated with ultraviolet (UV) light. Biodist
ribution, blood pool half-life, and MR image enhancement were determin
ed for PPLs composed of 10% of the gadopentetate dimeglumine lipid and
90% of ditricosadiynoyl tricosadiynayl phosphatidylcholine (DAPC) at
a dose of 0.015 mmol Gd+3/kg in rats, In T1-weighed MR images (TR/TE =
400/18 msec), an average signal enhancement of 34% in the kidneys and
20% in the liver was observed, which persisted for at least 90 minute
s after administration of the PPLs, Biodistribution studies using radi
olabeled PPLs confirmed that 80% of the injected dose remained in the
blood pool after 2 hours, The half-life of elimination from the blood
pool was 19 hours. The preparation was well tolerated in rats and prod
uced similar MR contrast enhancement of the blood pool as produced by
other liposome contrast agents, However, the half-life of PPL eliminat
ion from the blood pool was prolonged relative to other liposome syste
ms.