The goal of this project is to understand how membrane curvature regulates biochemical signals at the nano-bio interface. Here, the nano-bio interface refers to the physical interface between the cell membrane and nanoscale surface topography. We use nanofabrication to precisely engineer nanostructures that regulate the location, degree, and sign (positive or negative) of membrane curvatures in live cells. We found that membrane curvatures at the nano-bio interface induce significant changes of intracellular processes including endocytosis, actin dynamics, and mechanotransduction.
Bioelectric signals are crucial for physiological functions of rhythmic contraction of cardiomyocytes in the heart and communications of neurons in the brain. We use nanofabrication to develop electronic systems for detecting these small bioelectric signals. Specifically, we are developing vertical nanoelectrodes for scalable and non-invasive intracellular recording of cardiomyocytes. We are also developing mesh electrodes to record from organoids and tissues. We hope to achieve a broad impact by combining the development of new tools with applications to specific biological systems.
We are developing a new class of label-free optical electrophysiology for detecting neuroelectric signals. ElectroChromic Optical REcording (ECORE) utilizes the unique property of electrochromic materials that their optical absorption is a function of externally applied voltages. When neurons fire an action potential, the voltage will induce a localize color change of the electrochromic thin film, which allows us to optically read out electrical signals. By detecting reflection instead of fluorescence, ECORE avoids photobleaching and phototoxicity. The ECORE project takes a highly interdisciplinary approach of chemistry (electrochromic chemicals), physics (ultrasensitive optical detection), and biology (neuroscience).
We develop light-gated protein-protein interaction systems to control the activation and inactivation of intracellular signaling pathways. The ability to control signaling pathways by light offers unprecedented precision in temporal and spatial dimensions. Specifically, we are developing light-activatable molecular motors, light-activatable receptor tyrosine kinases, and light-activatable ERK and AKT signaling pathways.