[Pharmwaste] MIT's anti-microbial 'paint' kills flu, bacteria

[Tenace, Laurie]

>From the HCWH list serve (sorry about the double posting for some of you)

There is no mention of how this 'paint' might act in the environment - Laurie


MIT's anti-microbial 'paint' kills flu, bacteria
Coating's polymers poke holes in the membranes that surround influenza
viruses
Anne Trafton, News Office
November 30, 2006

A new "antimicrobial paint" developed at MIT can kill influenza viruses that
land on surfaces coated with it, potentially offering a new weapon in the
battle against a disease that kills nearly 40,000 Americans per year. 

If applied to doorknobs or other surfaces where germs tend to accumulate, the
new substance could help fight the spread of the flu, says Jianzhu Chen, MIT
professor of biology. 

"Because of the limited efficacies with existing (flu) vaccines and
antivirals, there's room for other, complementary approaches," said Chen, one
of the authors of a report on the new material that appeared Nov. 13 in the
online edition of the Proceedings of the National Academy of Sciences.

In a typical year, 200,000 people in the United States are hospitalized from
influenza virus infection, and 36,000 of them die, according to the Centers
for Disease Control. If an avian flu pandemic broke out, as many experts
fear, the death toll could be in the millions.

Most fatal flu cases occur in the elderly or in people with weakened immune
systems. Available flu vaccines are only 30 to 40 percent effective among
those groups, and only 70 to 80 percent effective among healthy adults.

Influenza is spread when viruses released by an infected person accumulate on
surfaces, where other people pick them up. Stopping the viruses before they
infect people could prevent some flu cases, says Chen.

The new substance can do just that, by killing influenza viruses before they
infect new hosts. The "antimicrobial paint," which can be sprayed or brushed
onto surfaces, consists of spiky polymers that poke holes in the membranes
that surround influenza viruses. 

Influenza viruses exposed to the polymer coating were essentially wiped out.
The researchers observed a more than 10,000-fold drop in the number of
viruses on surfaces coated with the substance, according to Alexander
Klibanov, MIT professor of chemistry and bioengineering and the senior author
of the paper.
Combating E. coli, too
The polymers are also effective against many types of bacteria, including
human pathogens Escherichia coli and Staphylococcus aureus, deadly strains of
which are often resistant to antibiotics. For example, S. aureus causes
serious problems in hospitals, where it can spread among patients and health
care workers. 

"In the U.S., more people die in hospitals of diseases they didn't have when
they got to the hospital than from the disease that prompted them to go to
the hospital in the first place," said Klibanov, who anticipates the new
material would be useful in a hospital setting, as well as others where
people congregate.

The new coating acts in a very different way from the many antibacterial
products--such as soaps, sponges, cutting boards, pillows, mattresses and
even toys--that are now on the market. 

Those products--which kill bacteria but not viruses--depend on a timed
release of antibiotics, heavy metal ions or other biocides, a system that has
many drawbacks, says Klibanov. Once all of the biocide has been released, the
antimicrobial activity disappears. Also, it can be harmful to release all of
these biocides into the environment. 

One of the benefits of the new polymer coating is that it is highly unlikely
that bacteria will develop resistance to it, Klibanov said. Bacteria can
become resistant to traditional antibiotics by adjusting the biochemical
pathways targeted by antibiotics, but it would be difficult for bacteria to
evolve a way to stop the polymer spikes from tearing holes in their
membranes.

"It's hard to develop resistance to someone sticking a knife in your body,"
Klibanov said.

In a prior experiment designed to test for resistance, 99 percent of bacteria
that were exposed to a polymer-coated surface died. The researchers then took
the surviving one percent, let them multiply and again exposed them to the
surface. They repeated the cycle 12 times, and each time, approximately 99
percent of the bacteria were killed, suggesting that the microbes were not
becoming resistant.

The MIT researchers are working with industrial and military partners such as
Boeing and the Natick Army Research Center to develop the coatings for
practical use. 

Once the polymer coating is applied to a surface, it should last about as
long as a regular coat of paint, Klibanov said. Accumulation of dead bacteria
and viruses diminishes the effectiveness of the nanometer-sized polymer
spikes, so the surface would need to be washed with soapy water every once in
a while to remove dead microbes, he said.

Other authors of the paper are Jayanta Haldar, a postdoctoral associate in
chemistry, and former MIT affiliates Deqiang An and Luis Alvarez de
Cienfuegos.

The research is funded by the U.S. Army, through MIT's Institute for Soldier
Nanotechnologies, and also by the National Institutes of Health.

A version of this article appeared in MIT Tech Talk
<http://web.mit.edu/newsoffice/techtalk-info.html>  on December 6, 2006
(download PDF) <http://web.mit.edu/newsoffice/2006/techtalk51-11.pdf> . 

Laurie J. Tenace
Environmental Specialist
Florida Department of Environmental Protection
2600 Blair Stone Road, MS 4555
Tallahassee, Florida 32399-2400
PH: (850) 245-8759
FAX: (850) 245-8811
Laurie.Tenace at dep.state.fl.us  
 
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