-
In the space that used
to house one transistor,
-
we can now fit one billion.
-
That made it so that a computer
the size of an entire room
-
now fits in your pocket.
-
You might say the future is small.
-
As an engineer,
-
I'm inspired by this miniaturization
revolution in computers.
-
As a physician,
-
I wonder whether we could use it
to reduce the number of lives lost
-
due to one of the fastest-growing
diseases on Earth:
-
cancer.
-
Now when I say that,
-
what most people hear me say
is that we're working on curing cancer.
-
And we are.
-
But it turns out
-
that there's an incredible
opportunity to save lives
-
through the early detection
and prevention of cancer.
-
Worldwide, over two-thirds of deaths
due to cancer are fully preventable
-
using methods that we already
have in hand today.
-
Things like vaccination, timely screening
-
and of course, stopping smoking.
-
But even with the best tools
and technologies that we have today,
-
some tumors can't be detected
-
until 10 years after
they've started growing,
-
when they are 50 million
cancer cells strong.
-
What if we had better technologies
-
to detect some of these more
deadly cancers sooner,
-
when they could be removed,
-
when they were just getting started?
-
Let me tell you about how
miniaturization might get us there.
-
This is a microscope in a typical lab
-
that a pathologist would use
for looking at a tissue specimen,
-
like a biopsy or a pap smear.
-
This $7,000 microscope
-
would be used by somebody
with years of specialized training
-
to spot cancer cells.
-
This is an image from a colleague
of mine at Rice University,
-
Rebecca Richards-Kortum.
-
What she and her team have done
is miniaturize that whole microscope
-
into this $10 part,
-
and it fits on the end
of an optical fiber.
-
Now what that means is instead
of taking a sample from a patient
-
and sending it to the microscope,
-
you can bring the microscope
to the patient.
-
And then, instead of requiring
a specialist to look at the images,
-
you can train the computer to score
normal versus cancerous cells.
-
Now this is important,
-
because what they found
working in rural communities,
-
is that even when they have
a mobile screening van
-
that can go out into the community
and perform exams
-
and collect samples
-
and send them to the central
hospital for analysis,
-
that days later,
-
women get a call
with an abnormal test result
-
and they're asked to come in.
-
Fully half of them don't turn up
because they can't afford the trip.
-
With the integrated microscope
and computer analysis,
-
Rebecca and her colleagues
have been able to create a van
-
that has both a diagnostic setup
and a treatment setup.
-
And what that means
is that they can do a diagnosis
-
and perform therapy on the spot,
-
so no one is lost to follow up.
-
That's just one example of how
miniaturization can save lives.
-
Now as engineers,
-
we think of this
as straight-up miniaturization.
-
You took a big thing
and you made it little.
-
But what I told you before about computers
-
was that they transformed our lives
-
when they became small enough
for us to take them everywhere.
-
So what is the transformational
equivalent like that in medicine?
-
Well, what if you had a detector
-
that was so small that it could
circulate in your body,
-
find the tumor all by itself
-
and send a signal to the outside world?
-
It sounds a little bit
like science fiction.
-
But actually, nanotechnology
allows us to do just that.
-
Nanotechnology allows us to shrink
the parts that make up the detector
-
from the width of a human hair,
-
which is 100 microns,
-
to a thousand times smaller,
-
which is 100 nanometers.
-
And that has profound implications.
-
It turns out that materials
actually change their properties
-
at the nanoscale.
-
You take a common material like gold,
-
and you grind it into dust,
into gold nanoparticles,
-
and it changes from looking
gold to looking red.
-
If you take a more exotic material
like cadmium selenide --
-
forms a big, black crystal --
-
if you make nanocrystals
out of this material
-
and you put it in a liquid,
-
and you shine light on it,
-
they glow.
-
And they glow blue, green,
yellow, orange, red,
-
depending only on their size.
-
It's wild! Can you imagine an object
like that in the macro world?
-
It would be like all the denim jeans
in your closet are all made of cotton,
-
but they are different colors
depending only on their size.
-
(Laughter)
-
So as a physician,
-
what's just as interesting to me
-
is that it's not just
the color of materials
-
that changes at the nanoscale;
-
the way they travel
in your body also changes.
-
And this is the kind of observation
that we're going to use
-
to make a better cancer detector.
-
So let me show you what I mean.
-
This is a blood vessel in the body.
-
Surrounding the blood vessel is a tumor.
-
We're going to inject nanoparticles
into the blood vessel
-
and watch how they travel
from the bloodstream into the tumor.
-
Now it turns out that the blood vessels
of many tumors are leaky,
-
and so nanoparticles can leak out
from the bloodstream into the tumor.
-
Whether they leak out
depends on their size.
-
So in this image,
-
the smaller, hundred-nanometer,
blue nanoparticles are leaking out,
-
and the larger, 500-nanometer,
red nanoparticles
-
are stuck in the bloodstream.
-
So that means as an engineer,
-
depending on how big
or small I make a material,
-
I can change where it goes in your body.
-
In my lab, we recently made
a cancer nanodetector
-
that is so small that it could travel
into the body and look for tumors.
-
We designed it to listen
for tumor invasion:
-
the orchestra of chemical signals
that tumors need to make to spread.
-
For a tumor to break out
of the tissue that it's born in,
-
it has to make chemicals called enzymes
-
to chew through
the scaffolding of tissues.
-
We designed these nanoparticles
to be activated by these enzymes.
-
One enzyme can activate a thousand
of these chemical reactions in an hour.
-
Now in engineering, we call
that one-to-a-thousand ratio
-
a form of amplification,
-
and it makes something ultrasensitive.
-
So we've made an ultrasensitive
cancer detector.
-
OK, but how do I get this activated
signal to the outside world,
-
where I can act on it?
-
For this, we're going to use
one more piece of nanoscale biology,
-
and that has to do with the kidney.
-
The kidney is a filter.
-
Its job is to filter out the blood
and put waste into the urine.
-
It turns out that what the kidney filters
-
is also dependent on size.
-
So in this image, what you can see
-
is that everything smaller
than five nanometers
-
is going from the blood,
through the kidney, into the urine,
-
and everything else
that's bigger is retained.
-
OK, so if I make a 100-nanometer
cancer detector,
-
I inject it in the bloodstream,
-
it can leak into the tumor
where it's activated by tumor enzymes
-
to release a small signal
-
that is small enough to be
filtered out of the kidney
-
and put into the urine,
-
I have a signal in the outside world
that I can detect.
-
OK, but there's one more problem.
-
This is a tiny little signal,
-
so how do I detect it?
-
Well, the signal is just a molecule.
-
They're molecules
that we designed as engineers.
-
They're completely synthetic,
and we can design them
-
so they are compatible
with our tool of choice.
-
If we want to use a really
sensitive, fancy instrument
-
called a mass spectrometer,
-
then we make a molecule
with a unique mass.
-
Or maybe we want make something
that's more inexpensive and portable.
-
Then we make molecules
that we can trap on paper,
-
like a pregnancy test.
-
In fact, there's a whole
world of paper tests
-
that are becoming available
in a field called paper diagnostics.
-
Alright, where are we going with this?
-
What I'm going to tell you next,
-
as a lifelong researcher,
-
represents a dream of mine.
-
I can't say that's it's a promise;
-
it's a dream.
-
But I think we all have to have dreams
to keep us pushing forward,
-
even -- and maybe especially --
cancer researchers.
-
I'm going to tell you what I hope
will happen with my technology,
-
that my team and I will put
our hearts and souls
-
into making a reality.
-
OK, here goes.
-
I dream that one day,
-
instead of going into
an expensive screening facility
-
to get a colonoscopy,
-
or a mammogram,
-
or a pap smear,
-
that you could get a shot,
-
wait an hour,
-
and do a urine test on a paper strip.
-
I imagine that this could even happen
-
without the need for steady electricity,
-
or a medical professional in the room.
-
Maybe they could be far away
-
and connected only by the image
on a smartphone.
-
Now I know this sounds like a dream,
-
but in the lab we already
have this working in mice,
-
where it works better
than existing methods
-
for the detection of lung,
colon and ovarian cancer.
-
And I hope that what this means
-
is that one day we can
detect tumors in patients
-
sooner than 10 years
after they've started growing,
-
in all walks of life,
-
all around the globe,
-
and that this would lead
to earlier treatments,
-
and that we could save more lives
than we can today,
-
with early detection.
-
Thank you.
-
(Applause)