2026-09-22T16:23:27Zhttps://api.repository.cam.ac.uk/server/oai/request

oai:www.repository.cam.ac.uk:1810/3469712025-12-20T02:30:37Zcom_1810_198332com_1810_256064col_1810_214775

A Lab-on-a-chip System for the Standardised Characterisation of Membrane Active Antimicrobials 10.17863/CAM.94385 Al Nahas, Kareem 0000000345685894 Keyser, Ulrich The continuing evolution of bacterial resistance against commercially available antibiotics is recognised as a global health threat, and the discovery of novel antimicrobials is urgently required. Antimicrobial peptides (AMPs) are emerging as important players in the fight against antibiotic resistance. In parallel, the field of microfluidics is maturing, and its benefits are being exploited in applications related to biomimicry and standardised testing. Developing a fundamental understanding of the modes of action of AMPs against membrane models is critical for developing these compounds into novel therapeutics. Throughout my studies, my efforts have been focused on developing microfluidic platforms that can streamline the evaluation of membrane active peptides in a systematic and standardised manner. As a result, I present the "GUV Studio", a bespoke multilayer microfluidic platform to quantify membranolytic efficacy and characterise the mode of action of AMPs. The platform is a biomimetic vesicle-based screening assay, which integrates an element for the high-throughput generation of Giant Unilamellar Vesicles (GUVs) in physiological salt concentrations on demand. Thousands of GUVs are individually immobilised downstream in hydrodynamic traps connected to separate perfusion inlets that facilitate the total fluid exchange of the solutions surrounding the vesicles, and enable the controlled, continuous administration of peptides for 8 different experiments in parallel. Membranolytic activity is expressed as a function of the time needed for an encapsulated dye to leak out of individual GUVs as a result of membrane permeabilisation or lysis. The platform has been used to study 20 native and de novo synthesised peptides at different concentrations. The results generated provide novel insights into the activity of a range of membrane active peptides, and demonstrate the capability of the lab-on-a-chip system to differentiate various modes of action defined by the response of the vesicle population to the peptides. My platform provides a quantitative, high-resolution tool to investigate the activity of any membrane-active compounds in a controlled, highly parallelised and high-throughput manner. University of Cambridge 2022-03-31 Thesis Doctoral Doctor of Philosophy (PhD) eng Cambridge-National Physical Laboratory (U.K.) studentship, the Winton Programme for the Physics of Sustainability, the Trinity-Henry Barlow Scholarship, and the ERC (Designer-Pores 647144) https://www.repository.cam.ac.uk/handle/1810/346971 https://www.repository.cam.ac.uk/bitstreams/c72ff65d-af4f-4099-aa95-e4f544ad2f39/download 11a323bfe1fb51cc9b8914d22450d9ef https://www.rioxx.net/licenses/all-rights-reserved/ Microfluidics antimicrobial peptides Membrane Giant Unilamellar Vesicles