Oral Presentation Australian Society for Microbiology Annual Scientific Meeting 2019

Liquid Metal Particles Used to Treat Pathogenic Mature Biofilms via Magneto-Physical Activation (#39)

Vi Khanh Truong 1 , Samuel Cheeseman 1 , Sheeana Gangadoo 1 , Daniel Cozzolino 1 , Russell Crawford 1 , Torben Daeneke 2 , Michael D. Dickey 3 , Aaron Elbourne 1 , James Chapman 1
  1. Nanobiotechnology Lab, School of Science, RMIT University, Melbourne, VIC, Australia
  2. School of Engineering, RMIT, Melbourne, Vic, Australia
  3. Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina , U.S.A.

Bacterial biofilms related infections are a significant medical issue, responsible for both large economic costs and serious health risks to patients. Once established biofilms are difficult to treat, as the presence of extracellular polymeric substances (EPS) and complex self-organised bacterial communities provides a protective environment for the pathogens. This is particularly true at the tissue-implant interface, as the biofilm often inhibits antibiotics treatment, meaning that the complete removal often required revision surgery. Recently, stimuli-activated nanotechnology-based treatments, such as photocatalytic, photothermal and magnetic hyperthermia nanoparticles have shown promise towards disrupting mature biofilm structures. However, such studies were unable to facilitate complete biofilm disruption. In this study, the applications of biocompatible liquid metals (LM), with magneto-physical antibacterial properties are investigated as a new class of stimuli-activated biofilm treatment. Particularly, Galinstan nanoparticles magnetically functionalised with low-weight ratio magnetic iron (Fe) inclusions are exploited as magnetic responsive materials. When exposed to a rotating magnetic field these particles move at high speeds and undergo a shape transformation from spheres to high aspect ratios rods, irregular spheroids, and “nano-stars” which can physically rupture and remove pathogenic bacteria from a model surface. The magneto-physical antibacterial activity of these LM particles is tested against a range of single and co-colonised infectious biofilms of common pathogens (Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli). Furthermore, the concentration of the magnetic Fe inclusion was varied in an effort to optimise the rate of antibacterial efficacy. This approach has paved the innovative way to treat the biofilm-related infections for the future applications.