The invention relates to a
polyethylene glycol / aliphatic
polyester / cationic
polymer amphiphilic triblock
copolymer. The
copolymer contains a hydrophilic non-ionic
polymer block, a hydrophobic block and a pH-sensitive cationic
polymer block.
Potassium hydride is taken as an initiator, the
polyethylene glycol and the aliphatic
polyester monomers and the cationic
monomer are sequentially added in a
polymerization reactor for respective reaction,
methanol is added for terminating the reaction; n-
hexane is used for the
precipitation and the purification of the triblock
copolymer in
tetrahydrofuran, the
precipitation is repeated for 3 times, and a product undergoes the
vacuum drying. The copolymer can form a
micelle or a
nanoparticle by self-
assembly in a water medium, wherein, a core of a loading
hydrophobic drug is formed by clustering the hydrophobic cationic
polyester block, the
polyethylene glycol block is assembled into a hydrophilic shell, thus having the functions of stabilizing the
micelle and effectively avoiding the capture and
protein absorption of a reticuloendothelial
system of an
organism; the cationic polymer block can be further acted with
DNA,
protein,
peptide and other biological macromolecules, thus forming the biodegradable and pH-sensitive
drug-loading polymer
micelle or the
nanoparticle which can be further dispersed,.