UCLA

Mechanical forces generated by cells play important functional roles within many physiological systems such as regulating local vascular resistance, producing cardiac contractions, and propelling intestinal contents. As a result, a multitude of disorders can be caused directly by malfunctioning cellular force generation including chronic conditions such as asthma, hypertension, and bowel disease. Such disorders place a significant burden on patient health and there is a paucity of effective drugs, arguably due to a lack of adequate tools for evaluating cellular force in research or in early drug discovery.

Existing approaches to measure cellular forces have been largely limited to biological research settings. Of these, the most widely used are traction force microscopy (TFM) and elastomeric micropost arrays (EMA). Although both approaches are useful for probing specific sub-cellular forces at low yields (usually 10s of cells per experiment), they were not intended to be used as high-throughput tools for rapidly conducting extensive pharmacological testing and have not been adopted by pharmaceutical companies for drug discovery. Specific barriers to adoption of such technologies include their relatively low throughput, complex experimental procedures which are difficult to automate, and minimal control over cell morphologies which necessitates intensive, non-trivial data analysis and normalization. Production of these systems and their physical characteristics also complicate or entirely prevent integration with standard SLAS well-plate formats.

We developed a high-throughput phenotypic screening platform that met this need by measuring the relative strains induced by the contractile forces generated by up to 105 single-cells adhered to large arrays of elastomeric surface sensors. The method supports analysis of a variety of force-generating behaviors in both a standalone and the multiwell formats used for drug-discovery. This dissertation describes the fabrication of these novel substrates, provides several use-cases including studies of smooth muscle or cardiac muscle force biology at the single-cell level, and provides novel biological data regarding the phagocytic forces of individual human macrophages.

We conclude by demonstrating the integration of the platform into standard 96- and 384-wellplates and verify its feasibility as a drug discovery tool by performing a pilot high-throughput screen to identifying potential bronchodilatory compounds for asthma management. These results indicate this platform could aid in the discovery of not only new therapeutic compounds, but also of novel molecular mechanisms associated with disease.