title: Tailored synthesis of intelligent polymer nanocapsules: an investigation of controlled permeability and pH-dependent degradability.
abstract: In this study, we present a new route to synthesize an intelligent polymer nanocapsule with an ultrathin membrane based on surface-initiated reversible addition-fragmentation chain-transfer polymerization. The key concept of our report is to use pH-responsive polydiethylaminoethylmethacrylate as a main membrane-generating component and a degradable disulfide bond to cross-link the membrane. The permeability of membrane, tuned by adjusting pH and using different lengths of the cross-linkers, was proven by showing a dramatic swelling behavior of the nanocapsules with the longest cross-linker from 560 nm at pH 8.0 to 780 nm at pH 4.0. Also, due to the disulfide cross-linker, degradation of the capsules using GSH as reducing agent was achieved which is further significantly promoted at pH 4.0. Using a rather long-chain dithiol cross-linker, the synthesized nanocapsules demonstrated a good permeability allowing that an enzyme myoglobin can be postencapsulated, where the pH controlled enzyme activity by switching membrane permeability was also shown.
authors.affiliation: Leibniz Institute of Polymer Research Dresden, Hohe Strasse 6, 01069 Dresden, Germany. huangxincn2008@yahoo.com
authors.forename: Xin
authors.initials: X
authors.lastname: Huang
authors.forename: Dietmar
authors.initials: D
authors.lastname: Appelhans
authors.forename: Petr
authors.initials: P
authors.lastname: Formanek
authors.forename: Frank
authors.initials: F
authors.lastname: Simon
authors.forename: Brigitte
authors.initials: B
authors.lastname: Voit
mesh_terms: D020341:Absorbable Implants; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000737:chemistry*; D004058:Diffusion; D006863:Hydrogen-Ion Concentration; D009211:Myoglobin / Q000008:administration & dosage / Q000737:chemistry*; D053769:Nanocapsules / Q000008:administration & dosage / Q000737:chemistry*; D010539:Permeability; D011108:Polymers / Q000737:chemistry*
chemical_list: D003692:Delayed-Action Preparations; D009211:Myoglobin; D053769:Nanocapsules; D011108:Polymers