VOICE OVER: This is a robotic shoulder
but inside it are human cells
undergoing a vigorous exercise routine.
This set-up has been developed to mimic the conditions of the human body - where
cells can be pushed and pulled and stretched in different directions.
If it works, one day human patients could be treated
with tissue grafts grown in robots.
Growing cells in a lab is easy enough.
They need nutrients, oxygen and something to grow in or on.
A Petri dish, for example, can give cells everything they need to thrive.
For Pierre Mouthuy however, a Petri dish wasn’t quite enough.
Pierre wants to grow tendon cells - the tough bits of tissue that connect muscles and bones.
He hopes lab-grown cells could one day be grafted into human bodies to repair tears
- in shoulder tendons for example. But there’s a catch.
PIERRE MOUTHUY: We’re still far away from a fully functional tendon tissue graft, and
we think that partially this is because we are not providing
the same complexity of mechanical stresses around those cells.
VOICE OVER: A Petri dish is not the natural home of a human cell,
and it seems that some cells need an environment
that’s a little bit more stimulating…
PIERRE: What researchers have shown, for a long time now, is that external mechanical stimulation
is really key to mature the tissue properly and to have the cells express the right type of genes
and to produce the right extra-cellular matrix.
VOICE OVER: Instead of a Petri dish or bioreactor flask, researchers grow tendon cells on stretchy plastic scaffolds,
with fluid providing the oxygen and nutrients.
This small chamber is Pierre’s team’s new flexible design.
So far scientists have used repeated stretching and relaxing
to stimulate the cells to grow properly.
But unidirectional stretching like this is pretty different from what tendons would experience in a real shoulder.
PIERRE: What the body is providing to native tissues is multiaxial mechanical stimulation
where you have three dimensional mechanical stresses being applied to tissue constructs,
in the form of not just tension but also compression and torsion.
VOICE OVER: Pierre’s new chambers can be pushed, pulled, bent
and twisted - just like a real tendon - but he still needed something to do all that pushing,
pulling, bending and twisting. What he needed, was a robot.
RAFAEL HOSTETTLER: What you’re seeing here is a ‘Robody’ and that’s a humanoid robotic avatar
and what makes them special is that they have muscles and tendons as we humans do.
So we try to imitate the way the human body works and we’re doing this because we believe
it’s going to help us to build robots that are eventually going to move just as natural and
graciously as human bodies do. They are being used in research, neuroscience, biomechanics
and so on but eventually they might be used to build better prosthetics and test new implants.
VOICE OVER: These robots are intended to mimic the shape,
the dimensions and the mechanics of the human body.
RAFAEL: And one day I got an email from a certain Pierre Mouthuy in my inbox asking
me whether I’d be interested of using his robots to put tendons on top of them and grow them. And
of course I was like hell yeah, that’s exactly in line with where we want to be going eventually.
VOICE OVER: Pretty soon, Pierre’s lab had their very own robot shoulder.
PIERRE: So what you can see is that one side of that chamber is being attached to the humerus
head, so the bone like structure that you see on this end, and the other side of the chamber
is attached to the string that is then linked to the motor which is acting as a muscle.
VOICE OVER: But Pierre wasn’t satisfied with an arm that just moves up and down.
PIERRE: So this is now a newer version of our robotic shoulder.
It allows us a more complete range of motion of the human shoulder, so not just abduction
adduction, but also this sort of rotation. You see that now the arm is moving in multiple directions.
VOICE OVER: This new method was designed to grow tendons to graft onto shoulder injuries,
but there are other possible applications…
PIERRE: To look at improving rehabilitation exercises, by looking at how the cells are
being affected by a particular exercise, or it could also be used in translational research to
screen through biomaterials to ensure that they are mechanically suitable for humans.
VOICE OVER: Now that they’ve developed the system to make it work,
the team’s next step is to figure out whether this new
'robotic Petri dish' can actually grow better tendons than the old-fashioned method.
PIERRE: So this has been years of work already.
And obviously now we’ve demonstrated that it is feasible to use this approach
and I think the fun only starts now because now that we’ve demonstrated that
it’s feasible to use those humanoid robots we can explore the different possibilities
that they can do and look into whether it can really help to improve the quality of the grafts
by providing these more physiologically relevant mechanical stresses.