Headache? Take a couple of aspirin. Knees sore in the morning? Ditto. Pollen or dust stuffing up your nose? Pop an antihistamine. High cholesterol, high blood pressure, high blood sugar? Your doc will pull out the prescription pad.
Microscopic medical robots have moved from science-fiction novels to medical texts. The development of tiny machines—nanobots that operate at the molecular level to diagnose and treat disease—has become a hot medical topic.
The first great hope is for cancer chemotherapy treatment. Chemotherapy is a bit like carpet-bombing a whole city to knock out one terrorist cell. The drugs attack both sick and healthy cells—and are very hard on the patient. Many effective drugs have been withdrawn because of toxicity, said Ido Bachelet of the Institute for Nanotechnology and Advanced Materials at Bar Ilan University in Israel in a YouTube presentation (www.youtube.com/watch?v=-5KLTonB3Pg). “We have amazing drugs—we just don’t know how to control them.” Nanobot therapy promises that control.
Sometime this spring, a patient with late-stage leukemia will receive DNA nanobot treatment. The nanobots are microscopic computers the same size as a human cell. They’re so small that a couple of thousand of them could dance on the tip of a human hair. Fashioned from snippets of DNA, they resemble a clamshell filled with chemotherapy drugs. One injection will contain millions of nanobots programmed to identify and cling to cancer cells and release the drugs, killing the diseased cells but leaving healthy surrounding tissue unharmed. Shortly afterward, the nanobots will disintegrate and be excreted.
If the therapy works as well in humans as it has in animals and insects, researchers predict the cancer will be gone in an astonishingly short time—perhaps as little as a month.
This prediction does not yet have oncologists and cancer researchers everywhere going out to buy fireworks. There are major technological roadblocks, such as how to reliably slip the devices past the vigilant immune system and how to get them to reliably perform inside the body and stick around long enough to complete their tasks. And discussion has started about major concerns like biosafety—protecting people from unforeseen negative consequences—and biosecurity—making sure nanotechnology is not used to produce bioweapons.
“I gotta tell you,” said one researcher in an online discussion, “my mind is screaming BS—but my heart is screaming revolution!”
Those who take the long view are betting on a revolution akin to germ theory and the development of antiseptics and antibiotics. Nanobots hold tremendous promise to diagnose disease at its earliest stages and deliver targeted treatments that make scalpels, radiography and systemic drugs seem crude. Addressing the problem from the inside out, as it were, also means less trauma to the body, less damage to healthy cells and a better and easier recovery.
Researchers are investigating how nanobots could be used to repair damaged spines, repair damage from heart attacks, treat diabetes and rheumatoid arthritis, even cross the blood-brain barrier to more safely remove clots and repair aneurysms in the brain. Nanobots could hitch rides on white blood cells, acting as the first responders when human tissue is damaged, to help repair tissue and speed up recovery from injury.
Medical College of Wisconsin researchers injected nanobots the size and shape of heart muscle cells to repair damage from heart attacks in mice. Organ function was restored and heart failure avoided. Lead researcher Paul Goldspink said he hopes next to adapt the technology to deliver pharmaceuticals for direct tissue regeneration. (www.sciencedaily.com/releases/2015/02/150204144659.htm).
Other researchers are looking at how nanobots could deliver drugs inside a clot in heart or brain blood vessels, shrinking or removing them and repairing the damaged vessels. This could replace some stent procedures, where small tubes are threaded through arteries in the groin or arm and into the brain or heart to capture and remove a clot or to place a small device to keep the blood vessel open—a procedure that itself can produce clots.
The U.S. Army, looking for better ways to treat brain trauma from bomb blasts, is involved in research to treat aneurysms with magnetized stents and nanoparticles to attract cells to repair the inner lining of blood vessels.
Nano ‘drones’ were used by researchers at Brigham and Women’s Hospital and Columbia University Medical Center to treat inflammation and remodel and stabilize plaque deposits in mice with advanced atherosclerosis—in just five weeks. (rt.com/usa/233871-drone-heart-attack-prevention).
The researchers are now into the next stage: fine-tuning the nanoparticles and the delivery system for use in humans. Nanobots could simultaneously deal with the plaque and attract immune cells to heal damaged arterial walls. Healing could be relatively quick, compared to years, even decades, of post-procedure drug therapy, and patients could remain healthier as there would be less interference with the infection-fighting ability of the immune system that accompanies long-term use of anti-inflammatories.
Bachelet believes nanobiotechnology will eventually replace many common medical procedures now used to diagnose and treat disease and injury. He’s talked about how nanotherapy can replace expensive surgical procedures, delivering therapy to the world’s poorest places, where hospitals, operating rooms and trained surgical staff are now unavailable due to cost (www.youtube.com/watch?v=aA-H0L3eEo0). He sees a day when patients could be inexpensively screened for a variety of diseases and chronic conditions whose impact can be blunted by early diagnosis and treatment. Family doctors will inject patients with nanobots that will send a cellphone alert when they encounter such things as cancer cells or plaque on blood vessel walls or high blood glucose.
So, are medical nanobots a pipedream, or a dream come true? We’ll know shortly.
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