title: New thiol-responsive mono-cleavable block copolymer micelles labeled with single disulfides.
abstract: Thiol-responsive symmetric triblock copolymers having single disulfide linkages in the middle blocks (called mono-cleavable block copolymers, ss-ABP(2)) were synthesized by atom transfer radical polymerization in the presence of a disulfide-labeled difunctional Br-initiator. These brush-like triblock copolymers consist of a hydrophobic polyacrylate block having pendent oligo(propylene oxide) and a hydrophilic polymethacrylate block having pendent oligo(ethylene oxide). Gel permeation chromatography and (1)H NMR results confirmed the synthesis of well-defined mono-cleavable block copolymers and revealed that polymerizations were well controlled. Because of amphiphilic nature, these copolymers self-assembled to form colloidally stable micelles above critical micellar concentration of 0.032 mg · mL(-1). In response to reductive reactions, disulfides in thiol-responsive micelles were cleaved. Atomic force microscopy and dynamic light scattering analysis suggested that the cleavage of disulfides caused dissociation of micelles to smaller-sized assembled structures in water. Moreover, in a biomedical perspective, the mono-cleavable block copolymer micelles are not cytotoxic and thus biocompatible.
authors.affiliation: Department of Chemistry and Biochemistry, Concordia University, 7141 Sherbrooke St. W., Montreal, Quebec, Canada H4B 1R6.
authors.forename: Behnoush Khorsand
authors.initials: BK
authors.lastname: Sourkohi
authors.forename: Rolf
authors.initials: R
authors.lastname: Schmidt
authors.forename: Jung Kwon
authors.initials: JK
authors.lastname: Oh
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000737:chemistry*; D002460:Cell Line; D004220:Disulfides / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008823:Micelles; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D004220:Disulfides; D008823:Micelles; D011108:Polymers; D013438:Sulfhydryl Compounds