Polymeric vesicle prepared from poly-l-lysine modified amphiphilic graft copolymer

摘要

Phospholipid vesicels (liposomes) and non-ionic surfactant based vesicles (niosomes) have been extensively studied as carriers of bioactive materials~1,2. In an effort to improve the stability of these vesicles, several polymerised vesicles have been developed~3,4, in which amphiphilic monomers containing polymerizable groups have been assembled into vesicles and later polymerised. In addition specially synthesised amphiphilic polymers in which the bilayer forming phospholipid amphiphiles are separated from the polymer backbone by an obligatory hydrophilic spacer unit have been used to make vesicles~5. In this laboratory, a novel poly-L-lysine based amphiphilic copolymer (PLP) has been developed by grafting hydrophobic palmitoyl groups and hydrophilic polyethylene glycol chains onto a poly-L-lysine backbone (Figure 1). It has been found that certain PLP variants can assemble into unilamellar vesicles on sonication in the presence of cholesterol and such vesicles are being investigated as gene delivery agents~6.