Cai, Liheng
Primary Appointment
Materials Science and Engineering
Contact Information
Wilsdorf 228
Charlottesville, VA 22904
Email: liheng.cai@virginia.edu
Website: http://softbiomatter.org/
Research Disciplines
Infectious Diseases/Biodefense, Materials Science, Molecular Physiology and Biological Physics, Physiology
Research Interests
Soft Matter Polymer Science Biophysics Biofilms
Research Description
Our lab's interests lie at the interface of soft matter and biology. We aim to understand and control the interactions between active soft materials, like responsive polymers or biological gels, and living systems, like bacteria or cells and tissues in the human body. We do this by using a combination of experimental and theoretical approaches; specific expertise includes polymer physics and chemistry, molecular engineering, macro- and micro-rheology, microscopy and image analysis, microfluidics and 3D printing. We focus on three directions: 3D printable soft materials. 3D printing has the potential of producing novel, structured materials with controlled features on multi-length scales, from microns to millimeters or larger. However, the basic materials available for 3D printing are limited: Plastics remain the most ubiquitous feedstock for industrial and desktop 3D printers. We explore new design principles to create 3D printable soft materials and use those materials to interface with soft biological objects. Human lung defense. As we are alive, we need to breathe; and this constantly brings in infectious particulates into our lung. The overarching question we are asking is: How can the human lung fight against numerous inhaled infectious particulates and maintain functional through its lifetime? We use microfluidics to create a novel human airway model to study why human lung defense works for healthy people but fails for patients with chronic lung disease, and use this model to discover therapeutics to restore human lung defense. Biofilms. Bacteria often live in complex environments such as gut and soil. Sometimes success bacteria transport does a good thing, but not if they dwell and form colonies or biofilms. Understanding and control interactions between bacteria and complex environments become essential in health and environmental science. Integrating polymer science, molecular engineering, single-cell fluorescence microscopy and microfluidics, we focus on how bacteria as an active swimmer influence the dynamics of surrounding matrices and formation of bacterial colonies or biofilms in mucus and soil. UNLEASH: We are looking for motivated undergraduates to join us! You don?t need to have any prior research experience: just be curious and eager to learn! Send Prof. Liheng Cai (liheng.cai@virginia.edu) an email briefly describing your background and interests, how much time you would like to spend in the lab, and what you hope to get out of your research experience. We currently have research projects for undergraduates available in the following research directions. 1. Biofilms in porous media. Understanding bacteria transport in porous media, like soil and filter membrane, is critical to environmental science and water filtration. Nevertheless, these porous media are opaque! You cannot see how bacteria swim there, or how they form colonies/biofilms and clog the porous media. In this project, you will focus on optimizing our newly developed ?transparent? model porous media, and use the state-of-art live cell fluorescence imaging technique to measure the behavior of single bacteria in porous media in real time. The goal of this project is to understand how the behavior of bacteria alters the microstructure of porous media, and how this, in turn, influences the flow transport in porous media. 2. Motility of bacteria in mucus hydrogels. In the human body, there are about 30 trillion human cells; by contrast, there are about 39 trillion bacterial cells, much more than that of human cells. Most bacterial cells live in mucus, a slimy hydrogel that covers our airway and gut. And the interactions between bacterial cells and mucus play an important role in human health. The goal of this project is to understand the behavior of a single bacterial cell in mucus: how it swims, when it stops, and how it forms colonies to impact the properties of mucus. We recently developed a new way to harvest endogenous mucus while keeping its properties intact. You will use the state-of-art microfluidic techniques to encapsulate a single bacterial cell in a droplet of mucus hydrogel and use fluorescence confocal microscope to monitor behavior of the cell in real time. By analyzing the cell behavior and quantifying the mucus properties, we hope to gain insights on how bacteria in mucus impact our health. For more details and other research directions, please visit our website: http://softbiomatter.org/