Core-clickable PEG-branch-azide bivalent-bottle-brush polymers by ROMP: grafting-through and clicking-to.

ABSTRACT: The combination of highly efficient polymerizations with modular "click" coupling reactions has enabled the synthesis of a wide variety of novel nanoscopic structures. Here we demonstrate the facile synthesis of a new class of clickable, branched nanostructures, polyethylene glycol (PEG)-branch-azide bivalent-brush polymers, facilitated by "graft-through" ring-opening metathesis polymerization of a branched norbornene-PEG-chloride macromonomer followed by halide-azide exchange. The resulting bivalent-brush polymers possess azide groups at the core near a polynorbornene backbone with PEG chains extended into solution; the structure resembles a unimolecular micelle. We demonstrate copper-catalyzed azide-alkyne cycloaddition (CuAAC) "click-to" coupling of a photocleavable doxorubicin (DOX)-alkyne derivative to the azide core. The CuAAC coupling was quantitative across a wide range of nanoscopic sizes (?6-?50 nm); UV photolysis of the resulting DOX-loaded materials yielded free DOX that was therapeutically effective against human cancer cells.

SUBMITTER: Johnson JA 

PROVIDER: S-EPMC3077470 | biostudies-literature | 2011 Jan

REPOSITORIES: biostudies-literature