Modification of egg phosphatidylcholine (eggPC) and dimyristoylphosphatidyl
choline liposomes with poly(ethylene oxide)-substituted lipids [PEO-lipid(
m,n ); m and n mean, respectively, the chain length of alkyl group and the
number of PEO segments]. Morphologies of these supermolecules were investig
ated by means of laser dynamic light scattering and transmission electron m
icroscopy. Reconstitution of the PEO-lipid to eggPC liposome was possible b
elow 40-50 mol% of total lipids for PEO- lipid(12,5), and 30-40 mol% for PE
O-lipid(12,13) and PEO-lipid(12,31). Effective encapsulation of FITC-dextra
n (1.96 kDa) into the liposome was obtained using the eggPC liposome modifi
ed with PEO-lipid. This PEO-modified liposome showed sufficient barrier fun
ction to water-soluble polymers such as dextran. Through various studies, i
t was found that PEO-lipid(12,13) is relatively compatible for modifying co
nventional eggPC liposome.