title: Dual Location Dual Reduction/Photoresponsive Block Copolymer Micelles: Disassembly and Synergistic Release.
abstract: Self-assembled micellar systems designed with multiple stimuli-responsive degradation have been considered as effective candidates for polymer-based delivery systems exhibiting enhanced/controlled release. However, most conventional approaches involve the incorporation of single, dual, or multiple cleavable linkages positioned at single locations, as in hydrophobic cores or at core/corona interfaces. Herein, a novel dual location dual reduction and photoresponsive block copolymer containing a disulfide linkage at the block junction and pendant o-nitrobenzyl thioether (NBS) groups in the hydrophobic methacrylate block (PEG-ss-PhvM) are reported, which are synthesized by a combination of controlled radical polymerization and facile coupling reaction. The amphiphilic design of the PEG-ss-PhvM enables the formation of self-assembled micellar aggregates with disulfides at the core/corona interfaces and pendant photocleavable NBS groups in the hydrophobic cores. The dual cleavable linkages respond to each stimulus (GSH or light), exhibiting enhanced release; further to a combination of dual locational stimuli, promoting synergistic release at dual locations.
authors.affiliation: Department of Chemistry and Biochemistry, Centre for NanoScience Research, Concordia University, Montreal, Quebec, H4B 1R6, Canada.
authors.forename: Tongbing
authors.initials: T
authors.lastname: Sun
authors.affiliation: Department of Chemistry and Biochemistry, Centre for NanoScience Research, Concordia University, Montreal, Quebec, H4B 1R6, Canada.
authors.forename: Puzhen
authors.initials: P
authors.lastname: Li
authors.affiliation: Department of Chemistry and Biochemistry, Centre for NanoScience Research, Concordia University, Montreal, Quebec, H4B 1R6, Canada.
authors.forename: Jung Kwon
authors.initials: JK
authors.lastname: Oh
mesh_terms: D004220:Disulfides / Q000737:chemistry; D005978:Glutathione / Q000737:chemistry / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D008823:Micelles; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D004220:Disulfides; D008823:Micelles; D011108:Polymers; D005978:Glutathione
keywords: block copolymers; controlled radical polymerization; drug delivery; enhanced release; stimuli-responsive degradation