Tiny Particles Solve Big Problems

Tag : Zirconium Compounds
"The idea is that by attaching these individual molecules of thedrug with a weak binding ability to the gold nanoparticle, you canmagnify their ability to bind," Melander says.

The researchers' theory proved correct. They started with amodified version of TAK-779, which didn't include the harmfulammonium salt. After testing, they found that attaching 12molecules of the modified drug (SDC-1721) to one nanoparticle ofgold restored the drug's ability to prevent HIV infection inprimary cultured patient cells. When only one molecule of the drugwas attached to the gold nanoparticle, the compound was unable toprevent HIV infection, indicating that the multivalency of the drugwas important for its activity.

"We've discovered a non-harmful way to improve the strength andefficacy of an important drug," Melander says. "There's no reasonto think that this same process can't be used with similar effecton other existing drugs."

Tiny Crystals Make a Stronger, More Durable Iron

Iron that is made up of nanoscale crystals is far stronger andharder than its traditional counterpart, but the benefits of this"nano-iron" have been limited by the fact that its nanocrystallinestructure breaks down at relatively modest temperatures. But the NCState researchers have developed an iron-zirconium alloy thatretains its nanocrystalline structures at temperatures above 1,300degrees Celsius  approaching the melting point of iron.

Kris Darling, a Ph.D. student at NC State who led the project todevelop the material, explains that the alloy's ability to retainits nanocrystalline structure under high temperatures will allowfor the material to be developed in bulk, because conventionalmethods of materials manufacture rely on heat and pressure.

In addition, Darling says the ability to work with the material athigh temperatures will make it easier to form the alloy into usefulshapes  for use as tools or in structural applications, such asengine parts.

The new alloy is also economically viable, since "it costsvirtually the same amount to produce the alloy" as it does tocreate nano-iron, Darling says.

Dr. Carl C. Koch, an NC State professor of materials scienceengineering who worked on the project, explains that the alloyessentially consists of 1 percent zirconium and 99 percent iron.The zirconium allows the alloy to retain its nanocrystallinestructure under high temperatures.

The research will appear in the journal Scripta Materialia . Kris Darling is the lead author on the paper, "Grain-sizeStabilization in Nanocrystalline FeZr Alloys," but co-authorsinclude Koch, fellow NC State materials science professor Dr.Ronald O. Scattergood, NC State doctoral student Jonathan E.Semones, and NC State undergraduates Ryan N. Chan and Patrick Z.Wong.

Source: North Carolina State University