Download Nanotechnology, the Future of Fighting Cancer?

2010
Nanotechnology, the
Future of Fighting
Cancer?
Bradley J. Kinnison
The University of North Carolina at Chapel Hill
11/16/2010
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COULD NANOTECHNOLOGY BE THE FUTURE OF FIGHTING CANCER?
NANOTECHNOLGY ADVANCES COULD BE THE TINY SOLUTION TO THE
WORLD’S MOST DANGEROUS DISEASE—CANCER.
Cancer Retreats from Nanotechnology Advances
BY BRAD KINNISON, November 23, 2010
The future of cancer prevention can fit into
the palm of your hand: in fact, a thousand of
them can. In an article from the British
Journal of Cancer, cancer specialists
Shiladitya Sengupta (BWH-HST Center for
Biomedical Engineering) and Ram
Sasisekharan (Biological Engineering
Division, Massachusetts Institute of
Technology) claim that nanotechnology is the
future of detecting cancer in its earliest stages,
Figure 1 Cancer cell metastasizes
snapping higher resolution photos of tumors,
and delivering chemotherapy drugs to tumors more effectively. This technology could very well
revolutionize the future of fighting cancer.
The best way to fight cancer is to catch it before it is too late, before it metastasizes and spreads
all over the body like, well, like a cancer. The question that has troubled scientists is how to
detect tiny cancer lesions that are too small for even modern medical imaging devices to see.
These larger machines and chemical sensors are not sensitive enough, which means that they
cannot easily ‘spot’ microscopic pockets of cancer. The answer may lie in nanotechnology.
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Nanotech cantilever sensors can ‘zoom in’ and spot these microscopic pockets of cancer because
of their tiny sensors. That may seem counterintuitive; how can a tiny sensor detect cancer better
than a larger one? This is one case where size does not matter.
The sensitivity of a sensor is determined by how much it vibrates when cancer molecules bump
into it. When miniscule cancer molecules run into a tiny nanotech sensor they jar the sensor more
than if the molecule had run into a larger sensor. This causes a higher vibration that is easier to
measure, resulting in higher sensitivity. These cantilever sensors have platform extensions,
almost like diving boards, that are engineered to bind to specific types of cancer cells. The sensor
detects cancer by
detecting the
bend in the diving
board when the
cancer cell lands
on it. Another
benefit of the tiny
size of the
nanotech sensor
is that it does not
allow room for
other non-cancer
Figure 2 Cancer molecules jumping on the ‘diving board’ of a nanotech cantilever sensor
molecules to bind
to it, which is one
of the biggest downfalls of cancer sensors used currently (such as PSA, prostrate serum antigen).
The small size of these nifty nanotech sensors also allows more of them to be put into the body at
one time in order to search for a wider variety of signs of cancer than a fat bulky sensor could.
These nanotech devices can be used for more than just detecting cancer earlier than ever
before—they are also revolutionizing tumor imaging.
Tumor imaging is vitally important to treating cancer because it allows oncologists (doctors who
specialize in cancer) to look at the physical changes in tumors and the tissue around them.
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Nanotech imaging devices called quantum dots (Qdots) have been engineered to enhance the
resolution of magnetic resonance imaging (MRI) photos of tumors to greater clarity than
technology has ever allowed before. The difference between Qdot enhanced photos and the
unenhanced MRI photos is like the difference in clarity between that picture you took with your
3 megapixel cell phone at your kid’s rec-league soccer game compared to the sports
photographer with his massive Hubble-space-telescope camera lens at the NFL football game on
Sunday night.
But how exactly do the Qdots help generate such high resolution photos of tumors? You may not
want to know the explanation, since it gets into the beautifully complex mess of quantum
physics. Suffice it to say that MRI photos are taken by measuring the magnetic ‘spin’ quantum
number of atoms, and these Qdots enhance the measurability of that spin state. These enhanced
MRIs have not been allowed yet in humans because the Qdots are highly metallic, which can
cause liver and kidney damage. The only way to avoid
this metal poisoning right now is to inject the Qdot in
small amounts below the toxic levels of the metal.
Researchers are already working on a solution to this
problem by attempting to create a protein ‘shell’ to
cover the Qdot until it reaches its target organ. The
scientists working on this ‘shell’ solution are confident
in the success of their research, saying that “it is only a
matter of time before we find the right protein
complex to encapsulate the Qdot.”
Figure 3 MRI of brain tumor
Nanotechnology is not only bringing about ground breaking advances in early cancer detection
and tumor imaging, but it is also showing up the competitors in effectively delivering
chemotherapy drugs. One of the problems of current chemotherapy delivery systems is that they
do not deliver the drugs efficiently, which is to say that not all of the drug makes it to the cancer
cells for which it was intended. Small amounts of drug are lost all along the way because the
body’s immune system is breaking down the ‘foreign’ drug delivery system. That would be like
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a UPS truck getting to its destination with only half of the packages it was supposed to be
carrying.
Nanotech drug delivery systems have recently been engineered to make them like an armored
truck, shielding these tiny devices from the immune system and carrying their payload directly to
target cancer cells while losing little of the drug along the way. These nanodelivery systems
deliver on average 3-10 times more drug to tumors than currently used chemo-transporters do.
Only the future will show how much using nanotechnology to deliver drugs will revolutionize
cancer treatment.