Repetitive Motion Speeds Nanoparticle Uptake

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Repetitive Motion Speeds Nanoparticle Uptake

http://www.medicalnewstoday.com/medicalnews.php?newsid=60253

Newly published research by Rice University chemists and North

Carolina State University toxicologists finds that repetitive

movement can speed the uptake of nanoparticles through the skin.

The research is based on in vitro experiments involving animal skin

that was exposed to buckyball-containing amino acids. It appears in

the Jan. 10 issue of the American Chemical Society's journal Nano

Letters.

" Our results confirm that repetitive motion can speed the passage of

nanoparticles through the skin, " said Monteiro-Riviere,

professor of investigative dermatology and toxicology at NC

State. " As more nanoparticles find their way into the workplace and

consumer goods, and as scientists look for innovative ways to use

nanoparticles to delivery drugs into the body, it is critical that

the nanoscience community identify these types of external exposure

factors. "

In the study, a solution of buckyball-containing amino acids were

placed on small sections of pig skin. In some experiments, the skin

was held still, and in others it was flexed for either an hour or an

hour and a half. Measurements were taken eight hours after exposure

and 24 hours after exposure.

The team found that the more the skin was flexed, the more

buckyballs it took up and the deeper they penetrated. Penetration

was also found to be deeper after 24 hours than after just eight.

Buckyballs, are spherical, soccer-ball-shaped molecules containing

60 carbon atoms. The buckyballs used in the study were part of an

innovative molecule called Bucky amino acid, or Baa, that was

created in the lab of Rice chemist Barron. Baa is a marriage

of buckyballs and phenylalanine, one of the 20 essential amino acids

that are the building blocks of all proteins.

" The findings were a bit surprising because the Bucky amino acids

tend to form spherical clusters that are up to 12 times larger in

diameter than the known width of intercellular gaps in the skin, "

said Barron, the W. Duncan Jr.-Welch Professor of Chemistry,

professor of materials science and associate dean for industry

interactions and technology transfer. " It's not clear why flexing

increases the uptake of fullerene peptides, but it will be important

to further investigate these mechanisms as we study the medical

potential of Bucky amino acids. "

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Co-authors include NC State graduate student Jillian Rouse and Rice

graduate student Jianzhong Yang.

The research was funded by the Environmental Protection Agency, the

National Academies Keck Futures Initiative and the Welch Foundation