- Title
- Reversible pH-triggered encapsulation and release of pyrene by adsorbed block copolymer micelles
- Creator
- Schatz, Christophe; Smith, Emelyn G.; Armes, Steven P.; Wanless, Erica J.
- Relation
- Langmuir Vol. 24, Issue 15, p. 8325-8331
- Publisher Link
- http://dx.doi.org/10.1021/la801127r
- Publisher
- American Chemical Society
- Resource Type
- journal article
- Date
- 2008
- Description
- The well-established ability of copolymer micelles to encapsulate and release hydrophobic molecules has been investigated following their adsorption onto silica particles. Here, a pH-responsive copolymer, poly(2-(dimethylamino)ethyl methacrylate)-b-poly(2-(diethylamino)ethyl methacrylate) (PDMA₁₀₆-b-PDEA₂₅), has been used to Study the formation and dissociation of adsorbed micelles through pH variation. This copolymer behaves as free unimers in aqueous solutions below pH 8 and forms micelles 29 nm in hydrodynamic diameter above this pH. Encapsulation and release of a model hydrophobic compound (pyrene) by in situ adjustment of the Solution pH has been compared for both free and adsorbed micelles using fluorescence spectrophotometry, epifluorescence microscopy, and ζ potential measurements. At basic pH values, pyrene is solubilized within the cores of micelles adsorbed on silica particles: addition of acid leads to micelle dissociation and release of the pyrene into the bulk aqueous solution. Micelle adsorption does not appear to hinder the extent of pyrene uptake/release. Moreover, this pH-responsive behavior is both reversible and reproducible over multiple pH cycles.
- Subject
- silica/aqueous solution interface; drug delivery; equilibrium; diblock copolymers; polymer micelles; thin films; adsorption kinetics; responsive; behavior; aqueous solution; fluorescence
- Identifier
- http://hdl.handle.net/1959.13/39581
- Identifier
- uon:4447
- Identifier
- ISSN:0743-7463
- Language
- eng
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