ACS News Service Weekly PressPac: May 15, 2006

• Heart Cut

• 232nd ACS National Meeting in San Francisco

Metals that float on water? A relatively new group of materials — metal foams — do exactly that, defying the conventional notion of metals as heavy and solid. In comparison, metal foams are mere wisps, consisting of more than 80 percent air. Having very high surface areas and continuous open cell porosity, they are finding applications in catalysis, surface enhanced Raman scattering (SERS), heat transfer, insulation and other areas.

Bryce C. Tappan and colleagues at the Los Alamos National Laboratory are reporting development of a new and simpler technique for making metal foams. Their report is scheduled for publication in the May 24 issue of the Journal of the American Chemical Society.

Technology for making metal foams has been limited mainly to aluminum and a handful of other metals. It produces either relatively heavy, dense foams or low-density foams with very large cell sizes. The new Los Alamos technique produces "unprecedented ultra-low density" foams with very small cell sizes from metals that could not be foamed in the past.

Some of the metal foams are lighter than Styrofoam™. Researchers used the technology to make foams from iron, cobalt, copper and silver. "This new technique shows promise for being a flexible, general approach to the formation of a wide range of new nanoporous metals not currently accessible by state-of-the-art nanoscience," they stated.

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The great promise of nanomedicine in opening a new era in diagnosis and treatment of disease depends heavily on the availability of versatile nanocarriers. The ultra-small counterparts of hypodermic syringes and IVs, nanocarriers are the containers that will carry and deliver nanodiagnostic and nanotherapeutics to their targets inside the human body.

Paras N. Prasad and colleagues at the University of Buffalo have developed a new genre of nanocarriers that not only hold their contents well, but can be guided to target tissue magnetically. Their report is scheduled for publication in the June 5 issue of Molecular Pharmaceutics. Prasad's group used the polymer-like molecule aggregates (polymeric micelles) to co-entrap magnetic nanoparticles and photodynamic therapy (PDT) drugs. A promising treatment for cancer and other conditions, PDT uses drugs that concentrate in diseased tissue and generate toxic molecules when exposed to laser light.

The nanocarriers, which are nanoscale clusters of polymeric molecules, magnetic nanoparticles and a PDT drug, demonstrated magnetic controllability and stability under physiological conditions and were efficiently taken up by living cells during in vitro experiments; magnetic guidance enhanced the uptake. The carriers' abilities to tightly encapsulate PDT drugs and target the diseased tissues with the magnetic guidance may minimize side effects that are a major drawback of PDT.

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A rare case of inhalation anthrax in February underscores just how much work remains before the United States is secure from terrorist attacks. That’s the conclusion of an article on the Vado Diomande incident, scheduled for publication in the May 15 issue of Chemical & Engineering News (C&EN).

Diomande, 44, an African dancer and drum maker, was the first naturally infected U. S. case of inhalation anthrax since 1976. The source of the infection: Untanned goat skins, which Diomande brought into the U. S. on a commercial flight from his home in Ivory Coast.

Written by Lois R. Ember, the C&EN article uses the incident to showcase gaps in security and preparedness for dealing with terrorist attacks. It points out, for instance, that the U.S. has fallen dangerously behind in efforts to develop mobile field hospitals for use in terrorist attacks. The Department of Homeland Security, which is responsible for developing a prototype hospital, has failed to do so. U.S. ports and borders remain porous to sources of anthrax and other possible terrorist weapons. And rapid tests for definitive diagnosis of anthrax are still unavailable.

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• Heart Cut
  Heart Cut offers weekly summaries of the hottest publications in chemistry-related journals. Last week’s collection includes new bactericidal titanium films; super polymers built to withstand the harsh environment of space; and a cutting-edge technology for assembling nanorod semiconductors. Try the cool RSS feed option for this website. RSS (Really Simple Syndication or Rich Site Summary) is a wonderful feature that delivers new items posted on the site straight to your computer, instantly and automatically. Click the orange RSS button to subscribe to RSS feeds for Heart Cut and other ACS publications.

September 10-14 is one of the year’s biggest and most influential scientific conferences – the 232nd ACS national meeting in beautiful San Francisco.

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