Development of Biomechanical Microtools for Investigating Live Cell Mechanobiology

Abstract

This thesis investigates the fundamental role of mechanical forces in cellular biology, with a specific focus on the mechanosensitive ion channel Piezo1 in regulating cell-matrix and cell-cell interactions. Using two complementary acoustic force-based platforms—the z-Movi cell avidity analyser and Acoustic Force Spectroscopy (AFS)—this research provides quantitative insights into cellular mechanobiology at both population and single-cell levels. The z-Movi studies for cell-matrix interactions revealed that Piezo1 significantly enhances cell adhesion to fibronectin during the initial attachment phase in both transformed (HEK293T) and tumor (MCF-7) cells, with overexpression enhancing adhesion and knockout or pharmacological inhibition reducing adhesion strength. Additionally, for cell-cell interactions, z-Movi analysis demonstrated the superior binding capacity of CD19-CAR T cells compared to HER2-CAR T cells and validated a novel bispecific adaptor approach to redirect CD19-CAR T cells to target HER2-expressing solid tumours. Further investigations using AFS elucidated Piezo1's critical role in cellular mechanoprotection, showing that beyond its ion channel function, Piezo1 structurally reinforces cell membrane integrity under mechanical stress. This work advances our understanding of mechanobiology in health and disease, offering insights into potential therapeutic strategies targeting mechanical signalling pathways in cancer and immunotherapy applications.