Biodegradable polyrotaxanes as a drug carrier

This article reviews our concept of drug delivery system using drug/polyrot axane conjugates ns a drug carrier. The biodegradable polyrotaxanes exhibit their supramolecular architectures: many cyclodextrins are threaded onto a single poly(ethylene glycol) chain capped with biodegradable bulky endgrou ps. The synthetic method of the polyrotaxanes, the conjugation with drugs, and their association nature in a physiological condition are described. Th e supramolecular dissociation of the drug/polyrotaxane conjugates via termi nal peptide cleavage by a hydrolytic enzyme is discussed in relation to the ir association nature. Through these studies, advantages of drug/polyrotaxa ne conjugates as a drug carrier are suggested in comparison with convention al drug/polymer conjugates.