CaIFF Webinar: Khay Fong

When lipidic nanoparticles meet a microbial living environment

Abstract

Lipid-based colloidal systems are widely used in pharmaceutical and food applications, where their performance depends on composition, self-assembled nanostructure, and the surrounding environment. Yet these materials are typically characterised under controlled conditions, while their intended biological environments contain complex microbial communities capable of actively modifying both the particles and their surroundings.

This work explores how representative members of the human skin and gut microbiomes interact with lamellar and non-lamellar lipidic nanoparticles (LNPs). Using synchrotron small-angle X-ray scattering alongside microscopy, drug-release and microbiological studies, we show that bacteria can drive substantial restructuring of lipid assemblies. In monoolein-based systems, bacterial exposure frequently promoted transitions towards structures with increasingly negative interfacial curvature, altering drug release by up to an order of magnitude. Screening 21 representative gut bacteria revealed restructuring of monoolein nanoparticles following exposure to approximately 75% of the species tested. Conversely, the effect of LNPs on bacterial survival was governed primarily by particle composition rather than internal nanostructure, with phytantriol showing substantially greater antimicrobial effects than monoolein or phospholipid systems.

Together, these findings reveal a bidirectional relationship between microbes and lipid colloids: bacteria can reshape lipid nanostructure and function, while lipid composition determines their impact on microbial survival. The microbiome should therefore be considered an active component of the environment in which pharmaceutical and food colloids operate.

Speaker

Dr Khay Fong is a Senior Lecturer in the School of Chemistry at Monash University and Director of the Master of Green Chemistry and Sustainable Technologies. She completed her PhD in Pharmacy at Monash University in 2013 and has since held research positions at ETH Zurich and the Adolphe Merkle Institute in Switzerland, as well as Monash University. Before returning to Monash in 2023, she was a Lecturer in Chemistry at the University of Newcastle. She is also a Director of the Australian Chapter of the Controlled Release Society (AusCRS).

Khay’s research focuses on lipid self-assembly and responsive nanomaterials for drug delivery. She is particularly interested in materials that respond to triggers such as temperature, light, pH and digestion, and in understanding how biological environments, including biomolecules and the microbiome, effect nanoparticle structure and behaviour.

Her research also extends to improving methods to understand how micro- and nanoplastics interface with human and environmental health.

Registration link to Zoom Event

https://ucph-ku.zoom.us/webinar/register/WN_dKOX_lg8QX6qjSeRb4wnkw