Carbon nano-structures — elixir or poison?

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Carbon nanostructures — elixir

or poison?

April 9, 2010 · Leave

a Comment

 

 

 

 

 

 

Buckyballs may compromise normal

organ development, leading to disease within a living organism. In

short, the tris buckyballs were toxic to human skin cells.

 

Moreover, the cells exposed to the

tris arrangement caused unique molecular level responses suggesting

that tris-fullerenes may potentially interfere with normal immune

responses induced by viruses. The team is now pursuing research to

determine if cells exposed to this form of fullerenes may be more

susceptible to viral infections.

 

 

physorg.com | Mar 31, 2010

 

A Los Alamos National Laboratory

toxicologist and a multidisciplinary team of researchers have

documented potential cellular damage from “fullerenes†—

 

 soccer-ball-shaped, cage-like

molecules composed of 60 carbon atoms. The team also noted that this

particular type of damage might hold hope for treatment of Parkinson’s

disease, Alzheimer’s disease, or even cancer.

 

The research recently appeared in Toxicology

and Applied Pharmacology and represents the first-ever observation of

this kind for spherical fullerenes, also known as buckyballs, which

take their names from the late Buckminster Fuller because they resemble

the geodesic dome concept that he popularized.

 

Engineered carbon nanoparticles, which

include fullerenes, are increasing in use worldwide. Each buckyball is

a skeletal cage of carbon about the size of a virus. They show

potential for creating stronger, lighter structures or acting as tiny

delivery mechanisms for designer drugs or antibiotics, among other

uses. About four to five tons of carbon nanoparticles are manufactured

annually.

 

“Nanomaterials are the 21st century

revolution,†said Los Alamos toxicologist Rashi Iyer, the principal

research lead and coauthor of the paper. “We are going to have to live

with them and deal with them, and the question becomes, ‘How are we

going to maximize our use of these materials and minimize their impact

on us and the environment?’â€

 

Iyer and lead author Jun Gao, also a Los

Alamos toxicologist, exposed cultured human skin cells to several

distinct types of buckyballs. The differences in the buckyballs lay in

the spatial arrangement of short branches of molecules coming off of

the main buckyball structure. One buckyball variation, called the

“tris†configuration, had three molecular branches off the main

structure on one hemisphere; another variation, called the “hexaâ€

configuration, had six branches off the main structure in a roughly

symmetrical arrangement; the last type was a plain buckyball.

 

The researchers found that cells exposed to

the tris configuration underwent premature senescence—

 

what might be described as a state of

suspended animation. In other words, the cells did not die as cells

normally should, nor did they divide or grow. This arrest of the

natural cellular life cycle after exposure to the tris-configured

buckyballs may compromise normal organ development, leading to disease

within a living organism. In short, the tris buckyballs were toxic to

human skin cells.

 

Moreover, the cells exposed to the tris

arrangement caused unique molecular level responses suggesting that

tris-fullerenes may potentially interfere with normal immune responses

induced by viruses. The team is now pursuing research to determine if

cells exposed to this form of fullerenes may be more susceptible to

viral infections.

 

Ironically, the discovery could also lead to

a novel treatment strategy for combating several debilitating diseases.

In diseases like Parkinson’s or Alzheimer’s, nerve cells die or

degenerate to a nonfunctional state. A mechanism to induce senescence

in specific nerve cells could delay or eliminate onset of the diseases.

Similarly, a disease like cancer, which spreads and thrives through

unregulated replication of cancer cells, might be fought through

induced senescence. This strategy could stop the cells from dividing

and provide doctors with more time to kill the abnormal cells.

 

Because of the minute size of nanomaterials,

the primary hazard associated with them has been potential

inhalation—similar to the concern over asbestos exposure.

 

“Already, from a toxicological point of view,

this research is useful because it shows that if you have the choice to

use a tris- or a hexa-arrangement for an application involving

buckyballs, the hexa-arrangement is probably the better choice,†said

Iyer.

 

“These studies may provide guidance for new

nanomaterial design and development.â€

 

These results were offshoots from a study

(Shreve, Wang, and Iyer) funded to understand the interactions between

buckyballs and biological membranes. Los Alamos National Laboratory has

taken a proactive role by initiating a nanomaterial bioassessmnet

program with the intention of keeping its nanomaterial workers safe

while facilitating the discovery of high-function, low-bioimpact

nanomaterials with the potential to benefit national security missions.

In addition to Gao and Iyer, the LANL program includes Jennifer

Hollingsworth, Yi Jiang, Jian Song, Paul Welch, Hsing Lin Wang,

Srinivas Iyer, and Gabriel Montaño.

 

Los Alamos National Laboratory researchers

will continue to attempt to understand the potential effects of

exposure to nanomaterials in much the same way that Los Alamos was a

worldwide leader in understanding the effects of radiation during the

Lab’s early history. Los Alamos workers using nanomaterials will

continue to follow protocols that provide the highest degree of

protection from potential exposure.

 

Meantime, Los Alamos research into

nanomaterials provides a cautionary tale for nanomaterial use, as well

as early foundations for worker protection. Right now, there are no

federal regulations for the use of nanomaterials. Disclosure of use by

companies or individuals is voluntary. As nanomaterial use increases,

understanding of their potential hazards should also increase.

 

 

 

 

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