Active targeting polymer micelle encapsulating drug, and pharmaceutical composition

Abstract

The present invention provides an active targeting polymer micelle encapsulating a drug, preventing an inappropriate release of a drug which may damage a normal cell. A polymer micelleincludes a backbone polymer unitthat has a target binding siteand a backbone polymer unitthat has a drugand is free from the target binding site, such polymer unitsandbeing disposed in a radial arrangement in a state where the target binding siteis directed outward and the drugis directed inward, in which: i) when the micelle is bound to a targetwhile maintaining the radial arrangement, the micelle is taken up into a cellsupplying the targetthrough endocytosis, and the drugis released into the cellby collapse of the radial arrangement in the cell; and ii) when the radial arrangement collapses in bloodbefore the micelle is bound to a target, the unitis excreted through metabolism, to thereby prevent a normal cell from being damaged by the drug