MechE Colloquium: Cellular crowd control: engineering collective cell mechanics for faster healing, better adhesion, and hydraulic ‘kidneybots’.

Abstract: Living tissues are communities comprised of many thousands of cells, and healing even a 1 mm skin wound is an exercise in massive crowd dynamics and swarm control. So, how can we heal faster or grow tissues better given this complexity? Our work applies principles from crowd mechanics, materials science, and swarm robotics to ‘herd’ cellular motion. Here, we will explore three stories related to this. 

First, we will discuss ‘outside-in’ tissue control where we have developed new strategies to ‘herd’ cellular motion inspired by sheepherding. Here, we use local electrical stimuli to control cellular speed and direction, enabling remote control of injury healing and tissue growth. These approaches are fundamentally limited by the engineering mechanics of crowds, and we will discuss how to develop control strategies here. 

Next, we will examine ‘inside-out’ tissue control where we hack swarm mechanics by building synthetic materials that mimic cells and integrate into living materials to control their function. In particular, we will look at our recent work using 3D nano printed ‘L’arc de triomphe’ tunnels to regulate and improve cell-material adhesion. 

Finally, we are developing a new type of living, soft actuator based on kidney tissue and collective control of water transport. Here, we use electrical cues to regulate ion transport and subsequent osmotic flux, allowing us to electrically control the hydrostatic pressure in living tissues and hydrogels, and we would especially appreciate feedback and advice here.  

 

Biography: Prof. Cohen is a joint Associate Professor of Mechanical and Aerospace Engineering and the Bioengineering Institute at Princeton University where he also serves as the Director of Graduate Studies for the Bioengineering Ph.D. Program. He did undergraduate training in Mechanical Engineering at Princeton University, followed by a Bioengineering Ph.D. at UC Berkeley/UCSF and a Cell Biology post-doctoral fellowship at Stanford University. When he is not in the lab, he is a professional storyteller, running the LabTales Science Storytelling training workshop and performing many times each year in theaters, nightclubs, universities, and museums around the world.