title: Assembly and degradation of low-fouling click-functionalized poly(ethylene glycol)-based multilayer films and capsules.
abstract: Nano-/micrometer-scaled films and capsules made of low-fouling materials such as poly(ethylene glycol) (PEG) are of interest for drug delivery and tissue engineering applications. Herein, the assembly and degradation of low-fouling, alkyne-functionalized PEG (PEG(Alk) ) multilayer films and capsules, which are prepared by combining layer-by-layer (LbL) assembly and click chemistry, are reported. A nonlinear, temperature-responsive PEG(Alk) is synthesized, and is then used to form hydrogen-bonded multilayers with poly(methacrylic acid) (PMA) at pH 5. The thermoresponsive behavior of PEG(Alk) is exploited to tailor film buildup by adjusting the assembly conditions. Using alkyne-azide click chemistry, PEG(Alk)/PMA multilayers are crosslinked with a bisazide linker that contains a disulfide bond, rendering these films and capsules redox-responsive. At pH 7, by disrupting the hydrogen bonding between the polymers, PEG(Alk) LbL films and PEG(Alk) -based capsules are obtained. These films exhibit specific deconstruction properties under simulated intracellular reducing conditions, but remain stable at physiological pH, suggesting potential applications in controlled drug release. The low-fouling properties of the PEG films are confirmed by incubation with human serum and a blood clot. Additionally, these capsules showed negligible toxicity to human cells.
authors.affiliation: Department of Chemical and Biomolecular Engineering, The University of Melbourne, Victoria 3010, Australia.
authors.forename: Melissa K M
authors.initials: MK
authors.lastname: Leung
authors.forename: Georgina K
authors.initials: GK
authors.lastname: Such
authors.forename: Angus P R
authors.initials: AP
authors.lastname: Johnston
authors.forename: Dhee P
authors.initials: DP
authors.lastname: Biswas
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Zhu
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Lutz
authors.forename: Frank
authors.initials: F
authors.lastname: Caruso
mesh_terms: D000327:Adsorption; D057219:Biofouling / Q000517:prevention & control*; D001798:Blood Proteins / Q000378:metabolism; D002214:Capsules; D057930:Click Chemistry / Q000379:methods*; D003432:Cross-Linking Reagents / Q000737:chemistry; D006801:Humans; D008856:Microscopy, Fluorescence; D011092:Polyethylene Glycols / Q000138:chemical synthesis* / Q000737:chemistry*; D013696:Temperature
chemical_list: D001798:Blood Proteins; D002214:Capsules; D003432:Cross-Linking Reagents; D011092:Polyethylene Glycols