AMPHIPATHIC BIODEGRADABLE BLOCK COPOLYMER HAVING POLYETHYLENEIMINE AS HYDROPHILIC BLOCK AND POLYESTER BASED POLYMER AS HYDROPHOBIC BLOCK AND SELF-ASSOCIATED POLYMER AGGREGATE FORMED THEREFROM IN AQUEOUS ENVIRONMENT

摘要

PROBLEM TO BE SOLVED: To provide a biodegradable block copolymer using a polyethyleneimine as the hydrophilic block and an aliphatic polyeste based polymer as the hydrophobic block, and a polymer associated product using the same. SOLUTION: A polyethyleneimine-polyester block copolymer can form polymer associated products having various sizes in an aqueous solution and exhibits a critical micelle concentration of as very low as about 10<-3> g/l compared to the conventional low molecular weight micelle. The encapsulation of a water- soluble drug or a hydrophobic drug in such a block copolymer associated product accelerates the solubilization of a difficultly soluble drug, and enables its use as the transmission system of a protein, a gene or a drug having a charge.