Understanding Surface Modifications Induced via Argon Plasma Treatment through Secondary Electron Hyperspectral Imaging

Nicholas Farr; Jeerawan Thanarak; Jan Schäfer; Antje Quade; Frederik Claeyssens; Nicola Green; Cornelia Rodenburg

doi:10.1002/advs.202003762

Understanding Surface Modifications Induced via Argon Plasma Treatment through Secondary Electron Hyperspectral Imaging

Adv Sci (Weinh). 2021 Jan 4;8(4):2003762. doi: 10.1002/advs.202003762. eCollection 2021 Feb.

Authors

Nicholas Farr^{1

2}, Jeerawan Thanarak^{1

2}, Jan Schäfer³, Antje Quade³, Frederik Claeyssens^{1

2}, Nicola Green^{1

2}, Cornelia Rodenburg¹

Affiliations

¹ Department of Materials Science and Engineering Sir Robert Hadfield Building University of Sheffield Mappin Street Sheffield S1 3JD UK.
² Insigneo Institute for In Silico Medicine The Pam Liversidge Building Sir Robert Hadfield Building University of Sheffield Mappin Street Sheffield S1 3JD UK.
³ Leibniz Institute for Plasma Science and Technology (INP e.V.) Felix-Hausdorff-Str. 2 Greifswald 17489 Germany.

Abstract

Understanding the effects that sterilization methods have on the surface of a biomaterial is a prerequisite for clinical deployment. Sterilization causes alterations in a material's surface chemistry and surface structures that can result in significant changes to its cellular response. Here we compare surfaces resulting from the application of the industry standard autoclave sterilisation to that of surfaces resulting from the use of low-pressure Argon glow discharge within a novel gas permeable packaging method in order to explore a potential new biomaterial sterilisation method. Material surfaces are assessed by applying secondary electron hyperspectral imaging (SEHI). SEHI is a novel low-voltage scanning electron microscopy based characterization technique that, in addition to capturing topographical images, also provides nanoscale resolution chemical maps by utilizing the energy distribution of emitted secondary electrons. Here, SEHI maps are exploited to assess the lateral distributions of diverse functional groups that are effected by the sterilization treatments. This information combined with a range of conventional surface analysis techniques and a cellular metabolic activity assay reveals persuasive reasons as to why low-pressure argon glow discharge should be considered for further optimization as a potential terminal sterilization method for PGS-M, a functionalized form of poly(glycerol sebacate) (PGS).

Keywords: argon plasma treatment; polymer characterization; polymeric biomaterials; secondary electron emission; secondary electron hyperspectral imaging.