Chemical and Physical Transformations of Silver Nanomaterial Containing Textiles After Modelled Human Exposure

Published: April 16, 2019

Author(s)

Danielle E. Gorka, Nancy J. Lin, John M. Pettibone, Justin M. Gorham

Abstract

The antimicrobial properties of silver nanomaterials (AgNM) have been exploited in various consumer applications, including textiles such as wound dressings. Understanding how these materials chemically transform throughout their lifecycle is necessary to predict their behavior during use and after disposal. The aim of this work was to evaluate chemical and physical transformations to AgNM-containing textiles during modeled human exposure to synthetic sweat or simulated wound fluid. This work focused on a commercial AgNM-containing wound dressing. Scanning electron microscopy with energy dispersive X-ray spectroscopy revealed the formation of micron-sized structures on the surface of the wound dressing after sweat exposure consistent with silver chloride formation. Measurements by X-ray photoelectron spectroscopy (XPS) confirmed these observations while X-ray diffraction (XRD) found a mixture of silver and silver chloride suggesting the commercial wound dressings contained zero-valent silver beneath the surface layer after 7 days of exposure. XRD and XPS- based findings suggested a comparable set of chemical states with wound fluid exposure with the addition of an adsorbed protein layer. Silver release was evaluated by inductively coupled plasma mass spectrometry which revealed a significant soluble silver fraction in the simulated wound fluid and minimal silver in the sweat solution, suggesting that the protein in wound fluid sequesters a fraction of the silver released due to dissolution, preventing complexation and reprecipitation on the surface as silver chloride. To evaluate the impact on antimicrobial efficacy, zone of inhibition (ZOI) testing was conducted which found that the wound dressing caused equal or larger ZOIs after modeled human exposure compared to the pristine wound dressing. The results presented here suggest AgNM-containing textiles studied in realistic media transform chemically resulting in a material with equal or greater antimicrobial prope
Citation: NanoImpact
Pub Type: Journals

Keywords

silver nanomaterials, textile, wound dressings, characterization, antimicrobial
Created April 16, 2019, Updated May 31, 2019