PROFESSOR: So there's a lot of images in the class,
partly because we're studying these materials
and you can see just with the ones sitting in front of me,
they have this porous, cellular structure.
So I show lots of images of materials.
We also look at how the images deform under load.
And I think, perhaps, that's something that
might be a little unexpected.
So for instance, we have a stage in the electron microscope
where we can actually deform things in the microscope.
And the stage is set up that it has a load cell on it.
And we could also measure how much it deforms, the materials.
So we can actually watch the materials as they're deforming.
So even though the cells may be 100 micron size,
you can watch how they deform and how they fail,
and you're going to learn a lot about the mechanics
from these sorts of observations.
So we have both video of these deformations and also
still photography at different time points that we show.
Another interesting little video clip that I show in the class
is we look at the interactions between biological cells
and tissue engineering scaffolds.
So for example, people who've looked
at trying to heal, say, burns in skin where there's
a large area of skin missing, one
of the ways that you can do that is
by using a collagen-based tissue engineering scaffold.
And when you have a burn in your skin
and it just heals the normal way and you get all the scar tissue
forming, that scar tissue is thought
to form in conjunction with a process of what's
called wound contraction.
So cells will actually migrate into the wound bed
and actually mechanically pull the edges of the wound
together, and that partly closes the wound and then scar forms
as well.
And those two processes are thought
to be related to each other.
So I've done a collaboration with Professor Ioannis Yannas
here at MIT who developed one of these scaffolds
for burn patients.
And he and I have been interested in this wound
contraction problem.
And it turns out if you just put fibroblast skin cells
into a dish of culture medium with one of these tissue
engineering scaffolds, they will contract the scaffold.
And you can use an optical microscope
to actually watch the cells do this.
So you can focus on an individual cell
and you can see the cell elongating.
You can see the scaffold itself contracting.
And you can see this whole process.
So this is one of the little video clips
that we show in class.
And the students always find that fascinating.