Novel Applications of Cold Atmospheric Plasma for the Decontamination of Bacterial Biofilm-Associated Wound Infection

Abstract

This research aims to investigate the biological interactions of cold atmospheric pressure plasma (CAP) with bacteria and to develop therapeutic hydrogel wound dressings which work in tandem with CAP treatment for the reduction of the bacterial bioburden of the wound while screening out any potentially harmful species generated by the CAP. The presence of a bacterial biofilm within a wound increases the risk of wound chronicity and bacterial biofilms are known to have increased antibiotic resistance. Wound infection can result in septicaemia. Chapter 3 characterises a helium-driven CAP (He-CAP) device pertaining to its clinical use through the quantification of the biologically relevant reactive oxygen and nitrogen species (RONS) it produces, operating temperature, the effect upon pH under varying operating conditions and how the He-CAP device interacts with a model hydrogel wound dressing (polyvinyl alcohol (PVA)). The optimised He-CAP operating parameters were then applied to planktonic and biofilm bacteria. Chapters 4 & 5 seek to understand the biological interactions between bacteria and He-CAP. Chapter 4 concerns the interactions between He-CAP and bacterial biofilm formation and oxidative stress response, through the assessment of RONS delivery through the developing bacterial biofilm. Chapter 5 assesses the mutagenic impact of sub-lethal He-CAP exposure, compares the mutagenic profile to known mutagens UV and ionising radiation and the impact upon antibiotic susceptibility. The final chapters focus on the development and assessment of therapeutic hydrogel wound dressings. Chapter 6 aims to develop a hydrogen peroxide responsive hydrogel which releases an antibiofilm agent to prevent biofilm formation. Chapter 7 seeks to utilise and characterise a novel argon-driven CAP (Ar-CAP) jet and to use a known antimicrobial, povidone-iodine (PVP-I) in a PVA hydrogel for synergistic killing of a Pseudomonas aeruginosa bacterial biofilm.

Date of Award	26 May 2021
Original language	English
Awarding Institution	University of Bath
Sponsors	The James Tudor Foundation & A & N Watson
Supervisor	Toby Jenkins (Supervisor), Tony James (Supervisor) & Young Amber (Supervisor)