RUI: Anomalous and motor-driven dynamics in crowded biomimetic networks

Scripps College, Claremont CA

Investigators

Abstract

Non-Technical Abstract As you read this sentence, billions of pieces of cellular cargo are being transported across the cells in your body via many tightly coordinated physical mechanisms. The inside of our cells is a crowded three-dimensional mesh which can restructure dynamically as needed. Physicists' current understanding of transport processes of small (micron-sized) particles is insufficient to explain what is actually observed when cells are placed under a microscope. This project will create "toy models" of cells on microscope slides and measure both the transport of small particles as well as the mechanical response of the sample corresponding to the different kinds of physical mechanisms driving the transport. In this way, the research team will empirically determine critical parameters needed to improve scientific models and theories on intracellular transport processes. Additionally, to help train, inspire, and diversify the next generation of scientists, each summer the principal investigator will volunteer with an existing pre-college outreach program to provide research opportunities to six high-achieving but underprivileged tenth-graders from the Los Angeles metropolitan area. They will then be mentored by faculty and current undergraduate students at Scripps College through their college applications and beyond. Technical Abstract The overarching goal of this project is to advance our understanding of the relationship between transport and mechanical properties within an active, biomimetic material far from equilibrium. Eukaryotic cells rely on targeted transport of molecules from < 1 nm to as large as > 1 μm across tens of microns in a dynamic, complex, and crowded environment to sustain life. In particular, molecules are corralled, mixed, and separated by emergent transport mechanisms where non-equilibrium dynamics and steric effects arising from molecular crowding both play crucial roles. The research team will create fully-tunable crowded and non-equilibrium biomimetic environments on microscope slides and simultaneously characterize the passive and active transport, network connectivity, force response, and viscoelastic moduli using a custom-developed optical trapping capable lightsheet microscope. This project aims to combine experimental results and accompanying theoretical models to generate predictions testable in vivo. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.