Category: Nanodot

from the backdate dept.
An article from the December 2001 issue of Mechanical Engineering magazine ("The engineered course of treatment", by Mauro Ferrari and Jun Liu), a publication of the American Society of Mechanical Engineers (ASME) is now available online. The article says, "Use of nanoscale devices is helping to revolutionize medical treatment and research." Ferrari is a professor of internal medicine and mechanical engineering and director of the Biomedical Engineering Center at Ohio State University in Columbus. Jun Liu is a doctoral candidate in his group.

In their article, Ferrari and Liu assert, "The ability to engineer devices and their components at the nanoscale level will revolutionize medicineóand the biomedical disciplines in general. There is a simple reason for this: Whatever we put into the body, in order to be therapeutically effective, must mimic the basic biological structure it replaces or augments. And biology is intrinsically and without exception multiscale, with hierarchies of ordered components comprising complex architectures of smaller, ordered components, all the way down to the molecular or atomic levelóthe nano level, precisely."

An item on the Nature Science Update website ("Magic bullet homes in", by Philip Ball, 4 March 2002) describes work by researchers at the University of Gottingen in Germany who have developed a custom-made drug molecule that turns lethal only when it reaches cancer cells. In healthy cells it is harmless, but it targets tumor cells selectively.

According to the NSU article, the Gottingen antitumour molecule is a ring of three carbon atoms that is highly strained and apt to burst open. Open, it is a reactive molecule that wreaks havoc among the nucleic acid molecules essential for normal cell function. The drug is delivered in the form of a 'prodrug' without the strained ring but with a sugar side-group. Once the sugar is clipped off, the molecule rearranges itself into a three-atom ring, and becomes lethally active. The Gottingen team uses an enzyme to cut away the sugar group. An antibody on the enzyme ensures that the enzyme targets the tumor cells, and activates the drug molecules there.

This method is vaguely similar to another molecular ësmart bombí that employs a single radioactive actinium atom contained inside a molecular cage and attached to a monoclonal antibody that homes in on cancer cells (see Nanodot post from 16 November 2001).

Gina Miller writes "Kenneth Sandhage, a materials chemist at Ohio State University in Columbus, realized based upon a meeting with marine biologist Monica Schoenwaelder, from the Alfred Wegener Institute for Polar and Marine Research in Bremerhaven, that her description of microshells created by diatoms could be practical microdevices. Sandhage has now teamed with a pharmacologist to develop drug delivery capsules and says: " Eventually, scientists may even seek to tinker with the DNA of diatoms to make tailored shapes." Turning Diatoms Into Nanodevices , on the inScight website (3/18/02)."

An article by Robert A. Freitas Jr. ("Nanomedicine: robots in the bloodstream") appeared in the October-December 2001 issue of Pathways, a quarterly journal published by Novartis, a major pharmaceutical company. In his article, Freitas, the author of Nanomedicine, reports on recent work on artificial biological nanomotors, nanotweezers, and dendrimers, and features descriptions and illustrations of respirocytes, clottocytes and microbivores, which are medical nanorobot concepts proposed by Freitas. He writes: "In just a few decades physicians could be sending tiny machines into our bodies to diagnose and cure disease. These nanodevices will be able to repair tissues, clean blood vessels and airways, transform our physiological capabilities, and even potentially counteract the aging process."

Freitas concludes: "Although nanotechnology is in its infancy, researchers are steadily making major breakthroughs. If we can learn to harness and precisely control the ability to manipulate molecules, then many aspects of our lives will change forever. In particular, the ability to carry out medical procedures at the molecular level will revolutionize medical practice. The next few decades will be very interesting indeed."

Pathways has a circulation of 20,000 and is sent to health care professionals in 53 countries around the world, so publication of the article represents a small but significant step into the mainstream for the concept of nanorobotic medicine.

More information on the specific medical nanorobots proposed by Freitas can be found in the technical articles that have appeared on the Foresight Nanomedicine web pages or in the IMM Reports that appear as part of his column on nanomedicine in the Foresight Update newsletter:

• Respirocytes: A Mechanical Artificial Red Cell (1998)
• Clottocytes: Artificial Mechanical Platelets (June 2000)
• Microbivores: Artificial Mechanical Phagocytes (April 2001). A more lengthy technical discussion appears as "Microbivores: Artificial Mechanical Phagocytes using Digest and Discharge Protocol" (March 2001) on the Zyvex Corp. website.

from the World-Watch dept.
The French newspaper Le Monde has posted a brief description of a presentation on "Therapeutic applications of nanotechnolgies" by Patrick Couvreur, a professor at the University of Paris-Orsay and a researcher with the French National Center for Scientific Research (CNRS), who spoke 31 January 2002 at a conference on "Nanotechnology and new medications". The web page provides links to audio files of the conference (in French).

If you donít read French, try the Babelfish/AltaVista machine translator.