How nanotechnology has been applied to cancer treatment
Nanotechnology and health sciences
In this article I hope to explain, in ordinary everyday English the term nanotechnology and how this science is applied to health and medicine.
Applied Nanotechnology Science and Medicine
I recently watched a program on cancer treatment and applied nanotechnology. What I came away with is this may be a whole new model for cancer research.
The program was carefully crafted and organized in such a way that the application of nanotechnology in medicine in general and as a form of cancer treatment in particular was easily explained.
Chemotherapy Background: Chemotherapy, the use of toxins to destroy cancer cells, has a long history dating back to the early 1920s. The problem with Chemo is that it not only destroys cancer cells it also attacks healthy ones. The effects can be so debilitating that some chemo patients lose their appetites along with their hair. Some have even reported that the chemo seemed worse than the cancer.
The toxins used in these drugs are known to inhibit cell growth A.K.A. mitosis. Since cells have a natural life-cycle inhibiting growth also means the eventual death of cancers.
Unfortunately the toxins used also affect other fast growing cells such as hair and the intestinal lining.
The trick, of course, is to inhibit the growth of fast growing cells just long enough to destroy the cancer.
The Other Problem with Chemo: Since chemotherapy drugs are molecules and molecules can cross through blood vessel walls they tend to spread throughout the patients body causing systemic problems nearly everywhere. These problems crop up as low white blood cell counts and can also reduce liver function and hamper kidney function. Without proper monitoring chemo can quite literally destroy these organs.
The molecules that make up these toxins are in the sub-nanometer scale.
Cancer & Blood vessel growth: It has been known for quite some time now that many cancers are capable of telling the body they need more blood. How this "instruction" is given and carried out isn't completely understood though some therapies attempt to take advantage of this by targeting blood vessel growth.
This "directive" is reflected in the extraordinary number of blood vessels often found feeding cancerous growths. Fortunately these blood vessels are different than normal ones; they tend to have holes and gaps in the vessel walls that aren't found in normal blood vessels.
Since these rouge blood vessels feed directly into cancerous cells taking advantage of their leaky nature could be yet another way to attack the growths.
Nanoparticles are larger than most molecules: A nanoparticle, being on the scale of 1 to 100 billionth of a meter, is still a larger "particle" than a molecule. After all, nanoparticles are typically a collection of molecules.
Mark E. Davis and Insert Therapeutics;
One Example of Applied Nanotechnology in Health Sciences
How the Delivery System was Created: Mark and his wife had gone through a harrowing cancer experience ten years earlier. She had breast cancer and it was spreading. A course of chemotherapy was prescribed and during one of her many sessions she implored her husband to find a better way to deliver the necessary drugs.
"You are a CalTech scientist; you people solve much bigger problems all the time. Do something about this."
So as his wife was getting one of her many weekly doses of chemotherapy Mark, a chemical engineer, would be in the hospital library studying medical literature on cancer.
As Mark later related he was "way out of my comfort zone."
He noticed a few things though and consulted with his wife's doctor.
After discussing what he learned with the doctor Mark felt he had hit on a novel approach to targeted drug delivery.
What he didn't know it would take ten years to develop the drug.
He knew if he could create a nanoparticle too large to pass through normal blood vessel walls, but small enough to pass through cancerous blood vessel holes he'd have a targeted delivery method. The trick would be to find a compound that would form itself into the 40 nanometer diameter balls. The compound would also have to be able to surround the toxic chemical.
If he could do that the nanoparticle would naturally end up at the site of cancerous cells which would promptly take up the starchy compound and the toxin right along with it.
Nanotechnology: A research and applied science that deals with physical objects that are from one to one hundred nanometers in size.
Nanometer: One billionth of a meter. 1/1,000,000,000.
Nanoscale: Objects that are from on billionth of a meter to one ten millionth of a meter. Or 1 to 100 nanometer sized objects.
Phase I Trials: Phase I trials ran for six months. After two months of clinical trials on a particular patient with lung cancer the growth of new lesions was completely arrested. After six months MRI scans showed void (or holes) in the larger cancer clusters indicating cancer cell death.
At no time did the patient suffer from any side effects. Since the phase one trial has concluded at last mention he was continuing to get this therapy via a compassionate use program.
The Phase I trial concluded in June of 2006.
Phase II Trials: Since the Phase I trials showed such promise Phase II trials are ongoing. This trial involves roughly one hundred people. Since the trial is current no data or results have been published thus far. As of July 2010 this is still the case.
Summary: Because a chemical engineer's wife implored her husband to "find a better way" nanoscale engineering has been put to use in a novel approach to chemotherapy. A nanoparticle surrounding a toxin is used to target the delivery of that toxin directly to the cancer via the cells unique characteristic of blood vessel formation.
I'm not about to propose that this is the magic bullet we've all hoped for in cancer treatment, but the I don't think the potential can be denied.