Antibacterial Surface Coatings from Zinc Oxide Nanoparticles Embedded in Poly(N-isopropylacrylamide) Hydrogel Surface Layers

Authors

  • Véronique B. Schwartz,

    1. Max Planck Institute for Polymer Research, Ackermannweg 10, 55122 Mainz, Germany
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  • Franck Thétiot,

    1. UMR CNRS 6521, Université de Bretagne Occidentale, 29285 Brest, France
    2. Foundation for Research and Technology–Hellas (FORTH), Institute of Electronic Structure and Laser (IESL), Nikolaou Plastira 100, Vassilika Vouton, 71110 Heraklion, Greece
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  • Sandra Ritz,

    1. Max Planck Institute for Polymer Research, Ackermannweg 10, 55122 Mainz, Germany
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  • Sabine Pütz,

    1. Max Planck Institute for Polymer Research, Ackermannweg 10, 55122 Mainz, Germany
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  • Lars Choritz,

    1. University Medical Center Mainz, BiomaTiCS research group, Department of Ophthalmology, Langenbeckstraße 1, 55131 Mainz, Germany
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  • Alexandros Lappas,

    1. Foundation for Research and Technology–Hellas (FORTH), Institute of Electronic Structure and Laser (IESL), Nikolaou Plastira 100, Vassilika Vouton, 71110 Heraklion, Greece
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  • Renate Förch,

    1. Max Planck Institute for Polymer Research, Ackermannweg 10, 55122 Mainz, Germany
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  • Katharina Landfester,

    1. Max Planck Institute for Polymer Research, Ackermannweg 10, 55122 Mainz, Germany
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  • Ulrich Jonas

    Corresponding author
    1. Macromolecular Chemistry, Department Chemistry and Biology, University of Siegen, Adolf-Reichwein-Strasse 2, 57076 Siegen, Germany
    2. Foundation for Research and Technology–Hellas (FORTH), Bio-Organic Materials Chemistry Laboratory (BOMCLab), Nikolaou Plastira 100, Vassilika Vouton, 71110 Heraklion, Greece
    • Macromolecular Chemistry, Department Chemistry and Biology, University of Siegen, Adolf-Reichwein-Strasse 2, 57076 Siegen, Germany.
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Abstract

Despite multiple research approaches to prevent bacterial colonization on surfaces, device-associated infections are currently responsible for about 50% of nosocomial infections in Europe and significantly increase health care costs, which demands development of advanced antibacterial surface coatings. Here, novel antimicrobial composite materials incorporating zinc oxide nanoparticles (ZnO NP) into biocompatible poly(N-isopropylacrylamide) (PNIPAAm) hydrogel layers are prepared by mixing the PNIPAAm prepolymer with ZnO NP, followed by spin-coating and photocrosslinking. Scanning electron microscopy (SEM) characterization of the composite film morphology reveals a homogeneous distribution of the ZnO NP throughout the film for every applied NP/polymer ratio. The optical properties of the embedded NP are not affected by the matrix as confirmed by UV-vis spectroscopy. The nanocomposite films exhibit bactericidal behavior towards Escherichia coli (E. coli) for a ZnO concentration as low as ≈0.74 μg cm−2 (1.33 mmol cm−3), which is determined by inductively coupled plasma optical emission spectrometry. In contrast, the coatings are found to be non-cytotoxic towards a mammalian cell line (NIH/3T3) at bactericidal loadings of ZnO over an extended period of seven days. The differential toxicity of the ZnO/hydrogel nanocomposite thin films between bacterial and cellular species qualifies them as promising candidates for novel biomedical device coatings.

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