title: Polymeric Multilayers that contain Silver Nanoparticles can be Stamped onto Biological Tissues to Provide Antibacterial Activity.
abstract: We report the design of polyelectrolyte multilayers (PEMs) that can be prefabricated on an elastomeric stamp and mechanically transferred onto biomedically-relevant soft materials, including medical-grade silicone elastomers (E'~450-1500 kPa;E'-elastic modulus) and the dermis of cadaver-skin (E'~200-600 kPa). Whereas initial attempts to stamp PEMs formed from poly(allylamine hydrochloride) and poly(acrylic acid) resulted in minimal transfer onto soft materials, we report that integration of micrometer-sized beads into the PEMs (thicknesses of 6-160 nm) led to their quantitative transfer within 30 seconds of contact at a pressure of ~196 kPa. To demonstrate the utility of this approach, PEMs were impregnated with a range of loadings of silver-nanoparticles and stamped onto the dermis of human cadaver-skin (a wound-simulant) that was subsequently incubated with bacterial cultures. Skin-dermis stamped with PEMs that released 0.25±0.01 μg cm-2of silver ions caused a 6 log10reduction in colony forming units ofStaphylococcus epidermidisandPseudomonas aeruginosawithin 12 h. Significantly, this level of silver release is below that which is cytotoxic to NIH 3T3 mouse fibroblast cells. Overall, this study describes a general and facile approach for the functionalization of biomaterial surfaces without subjecting them to potentially deleterious processing conditions.
authors.affiliation: Department of Chemical and Biological Engineering, University of Wisconsin, 1415 Engineering Drive, Madison, WI 53706 (USA).
authors.forename: Ankit
authors.initials: A
authors.lastname: Agarwal
authors.affiliation: Department of Surgery, School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Dr, Madison, WI 53706 (USA).
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Guthrie
authors.affiliation: Department of Pathobiology, School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Dr, Madison, WI 53706 (USA).
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Czuprynski
authors.affiliation: Department of Surgery, School of Medicine, University of Wisconsin-Madison, 600 Highland Ave, Madison, WI 53706 (USA).
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Schurr
authors.affiliation: Department of Surgery, School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Dr, Madison, WI 53706 (USA).
authors.forename: Jonathan F
authors.initials: JF
authors.lastname: McAnulty
authors.affiliation: Department of Ophthalmology and Vision Sciences, School of Medicine, Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, 1423 Tupper Hall, Davis, CA 95616 (USA).
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Murphy
authors.affiliation: Department of Chemical and Biological Engineering, University of Wisconsin, 1415 Engineering Drive, Madison, WI 53706 (USA).
authors.forename: Nicholas L
authors.initials: NL
authors.lastname: Abbott
keywords: Polymer-multilayers; microparticles; silver-nanoparticles; stamping; wounds