Nanomedicine - The Future of Medicine

A nanometer is one billionth of a meter. New science and technology based on the nanometer refers to the ability to manipulate individual atoms and molecules to build machines on a scale of nanometers or to create materials and structures from the bottom up with novel properties.

Nanotechnology, according to the National Science Foundation, could change the way almost everything is designed and made, from automobile tires to vaccines to objects not yet imagined. The concept is to prepare "smart objects" that can invade small spaces and target specific parts of the body. Some researchers expect nanoscience to have a profound impact on the way medicine is practiced.

The National Institutes of Health has established a "roadmap" to guide its research directions over the coming years and the roadmap includes specific reference to nanomedicine. "What if doctors could search out and destroy the very first cancer cells that would otherwise have caused a tumor to develop in the body? What if a broken part of a cell could be removed and replaced with a miniature biological machine? What if pumps the size of molecules could be implanted to deliver life-saving medicines precisely when and where they are needed?" These scenarios may sound unbelievable but they are the long-term goals of the NIH Roadmap to Nanomedicine Initiative that we anticipate will yield medical benefits as early as five to seven years from now.

Nanomedicine and biotechnology can be integrated and some see this as perhaps the most exciting scientific and economic development opportunity since the creation of the information technology revolution in the Silicon Valley several decades ago. They see the potential for major improvements in health care, the creation of revolutionary new "smart" materials and the development of a new generation of environmental sensors as real possibilities. They see that this can rapidly improve the ability to sequence the human genome, develop new techniques for characterizing the internal structure of cells, and allow scientists to duplicate the properties of the molecular machines found in living systems.

So let's consider nanodevices which have been defined by the government as meaning 1)smaller than 100nm (nanometers) - or much smaller than can even be seen with a microscope- with 2)a new function and 3)an ability to be controlled externally. The concept is that smaller is better and that recent advances in medicine and nanotechnology can converge. So scientists are making nanoparticles that can be controlled and that function in new ways and that can get to a cell or get inside the correct cell and deliver a payload such as a drug.

In the field of diabetes the great hope has long been to find a form of insulin that can be taken by mouth. Today, the enzymes in our stomachs and intestines break down the insulin before it can be absorbed into our blood stream. But scientists are trying to fabricate a porous silicone particle that can travel across the intestinal cell wall and deliver insulin instantly to the blood. If this could be done it would be like finding the Holy Grail of diabetes - oral insulin. The studies so far have demonstrated an increase in insulin transport across the cell wall by a factor of 10. This is not enough but it does show a proof of principle, which encourages those working in this field.

Here is another example. A "nanotube" can be formed from silicone dioxide or other similar materials. Actually they form naturally in the right setting but then can be designed to carry certain attachments such as drugs, antibodies or diagnostic devices or indeed all three of these. A nanotube can be made from a naturally magnetic material such as magnetite; can have drugs placed inside the tubule and can have a targeting molecule such as a monoclonal antibody placed on the surface of the tubule. Now the nanotubules are injected into the blood stream via a vein and travel through the body until that monoclonal antibody finds the site that it has been directed to such as a cancerous cell. The tubule now binds tightly to the cancer cell and because it is magnetic it can be detected with an MRI. Now we know where the cancer cell is and that our nanotube is attached to it, and the drug in the tube is now in high concentration right at the site of the cancer cell and nowhere else in the body. This is an example of how medicine can become personalized to the individual patient. In the United States about 1.4 million cases of cancer are diagnosed per year, and about 600,000 people die from it. More than 200 types of cancer exist, each with multiple subtypes or variants. With nanoparticles it should be possible to get right to that cancer - improving the diagnosis, imaging and treatment -- all done with one particle that can target just that cancer cell but not the normal cell, image the cancer cell and deliver the drug.

Here are some other approaches to cancer diagnostics. Another type of nanoparticle is a silicone based "nanowire" device. It is designed to recognize electrically minute levels of marker proteins that are over produced in cancer cells and which then circulate in the bloodstream. I mentioned magnetic emitting nanoparticles earlier. Some new techniques have created the ability to detect breast cancer cells in mice when the tumor is just half a millimeter in size - smaller than this letter o.

In the field of therapeutics any number of drugs or monoclonal antibodies can be attached nanoparticles and be potentially effective. Again the concept is to get the drug in high concentrations to exactly where it is needed yet not cause side effects with other cells in the body. This type of approach will mean producing "drugs" for each type of cancer. This is quite different than today's drug development approach of, more or less, one size fits all. As mentioned elsewhere and I will repeat here, the concept of personalized medicine means that drugs will be designed for increasingly specific indications. No one drug will be sold in large quantities. The large pharmaceutical companies are always looking for a "blockbuster" drug - a drug that they can sell more than a billion dollars worth of per year. Given this inclination, I wonder whether the big pharmaceutical companies will show an interest in this personalized medicine approach of individualized medications. If not, then smaller, entrepreneurial companies will pick up the slack.

For sure, nanomedicine's time is coming and it will have a major impact.

 

Last Modified: June 11, 2010


Copyright (c) Stephen C. Schimpff, MD