Category: Nanodot

from the self-assembling-bug-busters dept.
A research team at The Scripps Research Institute (TSRI) led by M. Reza Ghadiri have developed antibiotic agents based on self-assembling cyclic peptide nanotubes that which stack inside the cell membranes of bacteria and poke holes in the membranes, killing the cells. They reported on their research in the 26 July 2001 issue of Nature. The team synthesized rings of amino acids, the building blocks of peptides, which stack up to form tubes in bacterial cell walls. These self-assembling peptide nanotubes cleared infections of antibiotic-resistant bacteria in mice, even when injected far from the site of infection. Early work in this research project won Ghadiri Foresightís 1998 Feynman Prize in Nanotechnology for Experimental Work.

Read more for links to additional media coverage of this research.

from the early-nanomedicine dept.
MetaPhore Pharmaceuticals, based in St. Louis, Mo., announced on 12 July 2001 that it has completed initial human clinical studies of an artificial enzyme-mimic molecule that scavenges free radicals inside cells. MetaPhore says it is only the first candidate from its proprietary family of free-radical fighting enzyme mimetics.

The initial clinical trials showed the drug to be safe and well tolerated, according to the company press release. The studies are also significant because they represent the first time that a small molecule drug developed to mimic an enzymeís activity has been tested in humans, based on published reports. MetaPhore says its enzyme mimetics work by replicating the catalytic activity of the natural enzyme, superoxide dismutase (SOD), the bodyís natural defense against free radical damage to tissues and cells. The natural regulation of superoxide free radicals by SOD, however, is unbalanced in certain disease states, including cancer, when the bodyís immune system prompts an overproduction of superoxide and the natural SOD enzymes become overwhelmed.

The release also states that additional pre-clinical studies conducted by MetaPhore researchers and others indicate that SOD enzyme mimetics hold extensive potential for a wide array of diseases and conditions associated with free-radical damage, including pain and inflammation, stroke, heart attack as well as certain types of cancers. It is worth noting that some theories of aging mechanisms are associated with free-radical damage to tissue and cells.

from the digest-and-discharge dept.
In a recent technical paper, Robert A. Freitas Jr., author of Nanomedicine and a research scientist at Zyvex, describes an artificial mechanical phagocyte called a microbivore — the nanorobotic equivalent of a major class of natural blood cells — the white cells. Major antimicrobial defenses include circulating white cells capable of phagocytosis (engulfing and digesting other cells).

In his paper, Freitas presents a theoretical nanorobot scaling study for artificial mechanical phagocytes of microscopic size, called "microbivores," whose primary function is to destroy microbiological pathogens found in the human bloodstream using a "digest and discharge protocol". Freitas concludes microbivores would be up to 1000 times faster-acting than either natural or antibiotic-assisted biological phagocytic defenses, and about 80 times more efficient as phagocytic agents than macrophages, the white blood cells that are the primary cell-digesting agents in humans. He also notes: "Besides intravenous bacterial scavenging, microbivores or related devices may also be used to help clear respiratory, urinary, or cerebrospinal bacterial infections; eliminate bacterial toxemias and biofilms; eradicate viral, fungal, and parasitic infections; disinfect surfaces, foodstuffs, or organic samples; and help clean up biohazards and toxic chemicals."

A brief summary of the paper was published by the Institute for Molecular Manufacturing in Foresight Update #44. For much, much more information on the potential medical applications of advanced nanotechnology, see the Nanomedicine pages on the Foresight website.