Logo: University of Southern California

The Membrane Challenge

Professor Noah Malmstadt goes back to seventh grade
By: Rosalie Murphy
April 02, 2014 —

Noah Malmstadt’s work is, to the untrained eye, complicated. The chemical engineer, who holds a B.S. from Caltech and a PhD from the University of Washington, designs artificial cells – but here’s what’s written on his USC Viterbi profile page:

Lipid phase segregation leading to the formation of nanoscale lipid rafts is important in many cellular processes, including signaling and viral docking. Existing membrane model systems do not exhibit this nanoscale raft formation phenomenon: phase segregation in model membranes takes place on much larger scales. We are designing biomimetic systems that reproduce the nanoscale phase separation behavior observed in cells.

This fall we challenged Malmstadt to a “Membrane Challenge” – explaining his work to a seventh-grade science classroom at South Gate Middle School not just so the students could understand, but to keep them interested. What follows is a transcript of his presentation. See if you can keep up.

The "Membrane" Challenge with Noah Malmstadt from USC Viterbi on Vimeo.

"As an engineer, one thing I believe really strongly is that the best way to understand something is to try to build a copy of it. If you want to know how a car runs, one good way to understand it is to build your own car. I’m taking this approach to how cells function. I want to build a copy of a cell.

The copies I’m building are a lot simpler than real cells; we’re using the most basic chemicals we can get our hands on and using them to assemble things that kind of act like cells. I’m sure you’re all aware that cells are the basic unit of all biological systems – our bodies are made of cells, cells have specialized functions, there are particular things in the various tissues that they act in, they’re the building blocks of biology. And when I try to build copies of cells, I focus on the cell membrane. Our work really focuses on using these artificial cells to study important biological processes that affect the membrane.

One thing we’re really interested in is looking at how medicines get across the cell membrane. This is important is because a medicine that can cross the cell membrane by itself, without any proteins in the membrane interfering in the process, is a medicine that you can take as a pill. Otherwise it has to be a shot. A lot of people who are designing new medicines are very interested in how medicines get across the cell membrane, and they use our artificial cell membranes to study that process.

The other thing we study is how oxygen can damage the cell membrane. You might have heard of “antioxidants” – the reason antioxidants are important is because oxygen is a very damaging molecule. Oxygen makes metal rust, for instance.  In the same way it can damage cell membranes. Part of what happens in heart disease is oxidation of the cell membrane. So we’re developing artificial cell membranes to understand how oxygen can damage cell membranes, how it can change their mechanical properties, it can make them more stiff, and change their shape. That’s what we care about in my lab."

The students’ follow-up questions lasted an hour, ranging from “What would you do if you weren’t a professor?” (A: Probably work for a biotech company) to “What happens if the cell membrane gets blocked?” (A: Paralysis, seizure, or even death. A lot of powerful toxins block the cell membrane) and “How does the cell membrane help in evolution?” (A: Some people think the key step in the development of life is the emergence of membranes).