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PROFESSOR: So there's a
lot of images in the class,

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partly because we're
studying these materials

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and you can see just with the
ones sitting in front of me,

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they have this porous,
cellular structure.

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So I show lots of
images of materials.

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We also look at how the
images deform under load.

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And I think, perhaps,
that's something that

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might be a little unexpected.

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So for instance, we have a
stage in the electron microscope

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where we can actually deform
things in the microscope.

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And the stage is set up that
it has a load cell on it.

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And we could also measure how
much it deforms, the materials.

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So we can actually watch the
materials as they're deforming.

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So even though the cells
may be 100 micron size,

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you can watch how they
deform and how they fail,

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and you're going to learn
a lot about the mechanics

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from these sorts
of observations.

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So we have both video of
these deformations and also

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still photography at different
time points that we show.

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Another interesting little video
clip that I show in the class

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is we look at the interactions
between biological cells

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and tissue
engineering scaffolds.

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So for example,
people who've looked

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at trying to heal, say,
burns in skin where there's

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a large area of
skin missing, one

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of the ways that
you can do that is

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by using a collagen-based
tissue engineering scaffold.

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And when you have
a burn in your skin

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and it just heals the normal way
and you get all the scar tissue

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forming, that scar
tissue is thought

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to form in conjunction
with a process of what's

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called wound contraction.

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So cells will actually
migrate into the wound bed

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and actually mechanically
pull the edges of the wound

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together, and that partly closes
the wound and then scar forms

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as well.

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And those two
processes are thought

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to be related to each other.

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So I've done a collaboration
with Professor Ioannis Yannas

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here at MIT who developed
one of these scaffolds

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for burn patients.

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And he and I have been
interested in this wound

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contraction problem.

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And it turns out if you just
put fibroblast skin cells

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into a dish of culture medium
with one of these tissue

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engineering scaffolds, they
will contract the scaffold.

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And you can use an
optical microscope

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to actually watch
the cells do this.

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So you can focus on
an individual cell

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and you can see the
cell elongating.

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You can see the scaffold
itself contracting.

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And you can see
this whole process.

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So this is one of the
little video clips

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that we show in class.

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And the students always
find that fascinating.