Could nanomachines be tomorrow's doctors?

DNA computer diagnoses disease and dispenses drug.
29 April 2004

Scientists have built a tiny biological computer that might be able to diagnose and treat certain types of cancer. The device, which only works in a test-tube, is years from clinical application. But researchers hope it will be the precursor of future 'smart drugs' that roam the body, fixing disease on the spot.

Instead of silicon chips and electrical circuits, the minuscule machine is made of DNA. And rather than being controlled by electrical signals, it senses changes in its environment and responds by releasing biological molecules.

The biocomputer senses messenger RNA, the DNA-like molecule that helps create proteins from the information in genes. In particular, it can detect the abnormal messenger RNAs produced by genes involved in certain types of lung and prostate cancer.

When the computer senses one of these RNAs it releases an anticancer drug, also made of DNA, which damps expression of the tumour-related gene, researchers report in Nature¹.

From Science Daily:

Source: Oak Ridge National Laboratory
Date: 2004-04-28

Nanobiosensor Technology Gives New Access To Living Cell's Molecular Processes

OAK RIDGE, April 27, 2004 -- Researchers at the Department of Energy's Oak Ridge National Laboratory have developed a nanoscale technology for investigating biomolecular processes in single living cells. The new technology enables researchers to monitor and study cellular signaling networks, including the first observation of programmed cell death in a single live cell.

The "nanobiosensor" allows scientists to physically probe inside a living cell without destroying it. As scientists adopt a systems approach to studying biomolecular processes, the nanobiosensor provides a valuable tool for intracellular studies that have applications ranging from medicine to national security to energy production. [...]

Analysis: I remember a lecture on psychopharmacology, probably 15 years ago, during which the professor talked in great detail about the process of the synthesis and release of neurotransmitters, followed by a discussion of how the transmitter crosses the synapse and interacts with the receptor. The next slide said, simply: "Then Something Happens".

At that time, we really did not have much idea about what happened on a molecular level after the transmitter interacted with the receptor. We all knew, though, that the "something" that "happens" would be crucial to the next step in our ability to diagnose and treat mental illness. It has been noted here, and elsewhere in the 'sphere, that, current antidepressant medication, while useful, has serious limitations. The majority of our medications act by modulating transmitters and receptors in various ways. On 4/22/04, CC noted that there has been an advance in using a drug to affect G-protein-coupled receptor complexes to attenuate cocaine addiction in rats. This is the first example I have seen of a successful effort to alter the something that happens inside the cell, after the transmitter binds to the receptor. (The transmitter binds to the receptor on the outside of the cell membrane.) It might be another 20 years before anything truly useful comes of this, but with the development of nanobiosensor technology, and nanocomputers that sense cell conditions and release medications, we are sure to come up with something.

Last Sunday, my wife and I went to a farm north of Grand Rapids, Michigan, to pick up our mare, April. She had been bred to a stallion, and had been gone for about a week. It was the first time she had been separated from her colt. When we let her go into the pasture with the colt and two other horses, they had a joyous reunion. The four galloped, together, in circles around the pasture several times. I mention this because it was one of the finest displays of unbridled happiness that I have seen in a long time. This is the kind of emotion that a neuroscientist feels, when learning of the discovery of a whole new line of treatment that is under development.