Topic: Controlling nanotechnology scissors for medical uses

[Reno]

When your talking about tools that small your talking about surgeries that aren't planned and executed by the doctor. It would take not hours or days but probably months for a person to be able to enact change on a medical scale using tools that small. I see a day when tools this small are coordinated by nodes controlled by an interface. The day is coming when surgery will be an automated task.

Researchers in Japan have developed a pair of molecular-scale scissors that open and close in response to light. The tiny scissors are the first example of a molecular machine capable of mechanically manipulating molecules by using light, the scientists say.
The scissors measure just three nanometers in length, small enough to deliver drugs into cells or manipulate genes and other biological molecules, says principal investigator Takuzo Aida, Ph.D., professor of chemistry and biotechnology at the University of Tokyo.

?Chemists and biochemists may also use the scissors to precisely control the activity of proteins,? Aida says. He presented details of the new technique today at the 233rd national meeting of the American Chemical Society.

Scientists have long been looking for ways to develop molecular-scale tools that operate in response to specific stimuli, such as sound or light. Biologists, in particular, are enthusiastic about development of such techniques because it would provide them with a simple way to manipulate genes and other molecules.

?It is known, for example, that near-infrared light can reach deep parts of the body,? says Kazushi Kinbara, Ph.D., associate professor of chemistry and biotechnology at the University of Tokyo and co-investigator of the study. ?Thus, by using a multi-photon excitation technique, the scissors can be manipulated in the body for medicinal applications such as gene delivery.?

The scissors-like molecular machine uses a photo-responsive chemical group that extends or folds when light of different wavelengths falls upon it.

Just like "real" scissors, the molecular scissors consist of a pivot, blades and handles. The pivot part of the scissors is a double-decker structure made of chiral ferrocene, with a spherical iron (II) atom sandwiched between two carbon plates. The three-piece unit creates a shaft that allows the scissors to rotate and swivel.

Driving the motion are two handles strapped with photo-responsive molecules called azobenzene, which not only has the ability to absorb light, but comes in two isomeric forms: a long-form and short-form. Upon exposure to UV light, the long-form of azobenzene is converted into the short-form. Exposure to visible light transforms the short-form into the long-form.

When UV and visible light are used interchangeably, the length of the azobenzene decreases and increases, which drives the handles in an open-close motion. The movement activates the pivot, followed by an opening-closing motion of the blades.

Attached to the scissors? blades are organometallic units called "zinc porphyrin." When the zinc atom in the zinc porphyrin binds with a nitrogen-containing molecule, such as DNA, the zinc and nitrogen act like magnets, securing a firm grip on the molecule.

?As the blades open and close, the guest molecules remain attached to the zinc porphyrin, and as a result, they are twisted back and forth,? Kinbara says.

In a recent study, the scientists demonstrated how the light-driven scissors could be used to grasp and twist molecules. The group is now working to develop a larger scissors system that can be manipulated remotely. Practical applications still remain five to 10 years away, the scientists say.

http://www.physorg.com/news94042930.html

[Clive]

And this is merely 21st century medicine Bob.  I wonder what will they be doing by the 25th century?   

[Reno]

Makes you wonder if there will be such a thing as medicine in the 25th century. I think the idea of a body that gets damaged and fails will be a horrible and abstract concept to us one day.

[Clive]

The problem is that we have to die in order to make way for new generations.  Perhaps there will be a cut-off age where we have to undergo mandatory euthanasia?   150 perhaps? 

[Reno]

I hate to sound like a tv show, but hey governments today are planning missions to set installations up the moon and mars. Why must we be teathered to this rock? Lets face it whether we live forever or not the population is still going to rise.

[Clive]

Add both the Moon and Mars together and you still don't end up with a decent sized planet.  With our present rate of growth we would have to colonise extrasolar planets long before we can reach them unless we can build spacecraft that will be capable of relativistic speeds.  Culling is the only answer Bob.

[Reno]

Would you want to live on a ring world clive?

http://en.wikipedia.org/wiki/Ringworld

[Clive]

I suppose we could adapt to almost any situation Bob.  It's certainly a possible answer for future needs yet I can't help thinking that severe population control is the only real answer.

[Reno]

Your probably right. Something like ring world is complete fiction I know, but there will be many innovations that come along that will completely change our perspective on todays problems.

I've heard that many of the 1st world countries are actually having trouble maintaining their populations where on the other hand most of the 3rd world countries are having trouble curbing it. I think if the quality of life were to be brought up in combination with a mild population control program, the global population probably could be tackled.