The technological edge to our lives: Nanomedicine

Consider the idea of tiny nanomachines traveling your bloodstream, designed to home-in on specific types of tissue. If these come to pass, you might program these machines to congregate at the vessels that supply blood to cancerous tumors, choking-off the blood supply and thereby killing the tumor. Or how about nanomachines that target the lymphatic vessels that drain tumors -- close them down and the tumor might also be shut down. But this isn't science fiction -- it's just another example of sci fi coming true (at least in the laboratory, so far) -- researchers at the Burnham Institute and UCSD's Jacobs School of Engineering have combined nanotechnology and biology to successfully home in on these specific tissue types!

According to the 9/11 MIT Technology Review these folks,"...programmed miniature, nanocrystalline semiconductor particles, called quantum dots ("qdots"), and wrapped them with tiny pieces of protein that home to specific addresses inside living tissue ("homing peptides")."

Sangeeta Bhatia, developer of these qdots, summed up their excitement, "We are enthusiastic about these results because we showed that qdots could be successfully used inside the body without causing blood clotting, and because the homing peptides successfully directed the qdots to a specific type of cancer, in this case, breast
cancer.

High Tech Tattoos.

The system starts with a very high-tech tattoo. But instead of ink that is absorbed by cells, this tattoo uses polyethylene-glycol beads, which are coated with fluorescent molecules, which happen to be just a bit larger than ink molecules. Which is quite important, because this allows the tattoo to remain in the interstitial fluid between cells, where glucose levels closely mirror the glucose levels in the blood. (Why not let the molecules enter the cells like traditional tattoo ink? Because the glucose within cells is rapidly converted to energy and so would show consistently low levels.)

Because the tattoo's molecules fluoresce more brightly as the glucose levels fall, a watch or other sensor over the tattoo can track and record glucose levels, and alarm the wearer when necessary. I can also imagine that this technique might be very useful for future embedded dispensing devices that might do away with constant insulin injections. 

Of course this tattoo is still in the laboratories, but it seems to be working on rats, which is a good initial indication. And it is most certainly, "out of the box!"

Better "Video Cards" For Restoring Sight!

On another NBIC front, Ken points us to a September 5 announcement from Sandia National Labs that describes work going into an artificial retina that would generate "1,000 points of light;" it's in the form of an array of MEMS stimulators that could stand-in for damaged rods and cones, or for eyes damaged by certain diseases. The camera would sit on eyeglasses, and it would send the image data and the power run the implant (at the back of the eye) via a radio signal!

Of course a 1,000-point array is far coarser than normal eyesight's million or so pixels, but it could free up otherwise blind people to be far more self-sufficient.

And things will only get better:

"Compared to the elegance of the original biological design, what we're doing is extremely crude," says Wessendorf. "We are trying to build retinal implants in the form of electrode arrays that sit on the retina and stimulate the nerves that the eye's rods and cones formerly served."

"The size of cones and rods, as well as nerve connections, are in the micron range -- a difficult but doable realm for scientists used to working with
micromachines.

'We'll use a crude, shotgun approach that fires groups of nerves. In the long run, of course, we'd like to stimulate each individual nerve.'"