In the 1966 sci-fi movie Fantastic Voyage, a team of doctors shrank down and traveled in a tiny submarine through a Russian scientist's body to remove a blood clot in his brain. Though science hasn't figured out how to shrink doctors, it has been able to make tools to treat cancer and other diseases smaller than a human cell.
The processes inside our bodies that give rise to cancer happen at the nanoscale -- a size of 1 to 100 nanometers. To give you an idea of how small that is, a human hair is about 100,000 nanometers wide.
Nanotechnology diagnoses and treats disease at this very tiny level. It uses nanoparticles -- particles that are 100 to 10,000 times smaller than human cells. Their small size helps them locate and kill cancer more precisely than current cancer treatments.
How Does Nanotechnology Diagnose Cancer?
Today, doctors often order imaging tests like X-rays, CT scans, and MRIs to help diagnose cancer. But these tests can find the disease only once it's big enough to see. By then, the cancer may have copied itself many times and spread to other parts of the body. These scans also can't show whether a tumor is cancer or not. You usually need a biopsy to know for sure.
Because of its small size, nanotechnology can detect changes in a very small number of cells. It can tell the difference between normal and cancer cells. And it can get to cancer at its earliest stages, when the cells have just started to divide and the cancer is easier to cure.
Nanotechnology can make tumors easier to see on imaging tests. Coating nanoparticles with antibodies or other substances helps them find and stick to the cancer cells. Particles can also be coated with substances that send out a signal when they find cancer. For example, nanoparticles made from iron oxide bind to cancer cells and send off a strong signal that lights up the cancer on MRI scans.
Nanotechnology can also help doctors locate cancer in blood or tissue samples. It can spot pieces of cancer cells or DNA that are too small for current tests to pick up.
How Does Nanotechnology Treat Cancer?
Nanotechnology can help to make cancer treatments safer and more precise.
Specially designed nanoparticles deliver medicines like chemotherapy straight to the tumor. They don't release the medicine until they reach it. This stops the drugs from damaging healthy tissues around the tumor. That damage is what causes side effects.
The small size of nanoparticles allows them to deliver medicines into areas of the body that would normally be hard to reach. One example is the blood-brain barrier, which prevents toxic substances from getting into the brain. It also blocks some medicines. Nanoparticles are small enough to cross this barrier, which makes them a useful treatment for brain cancer.
Is Nanotechnology Now in Use?
Abraxane is a nanoparticle made from the protein albumin attached to the chemo drug docetaxel. It stops cancer cells from dividing. Abraxane treats breast and pancreatic cancers that have spread, and non-small-cell lung cancer.
Doxil is the chemo drug doxorubicin wrapped inside a liposome, a fatty sac. It disrupts cancer genes so the cancer cells can't divide. Doxil treats ovarian cancers, multiple myeloma, and Kaposi's sarcoma.
Researchers are studying other nanotechnology treatments in clinical trials. Some of these treatments wrap toxic drugs in nanoparticles to make them safer, or to help the drug survive the trip through the bloodstream. One day, nanoparticles might also be able to deliver radiation to cancer.
Does Nanotechnology for Cancer Have Side Effects?
Nanotechnology targets cancer cells more exactly to spare healthy tissues. In theory, it should cause fewer side effects than current treatments like chemotherapy and radiation.
Current nanotechnology-based treatments such as Abraxane and Doxil do cause side effects like weight loss, nausea, and diarrhea. But these problems may be from the chemotherapy drugs they contain. Researchers should learn more about the side effects of these treatments as they study them in clinical trials.