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Dr.
Nancy Monteiro-Riviere's office is a study in contrasts. While the
walls in her office in the College of Veterinary Medicine (CVM) bloom
with
her children's colorful drawings and love notes, the desk and bookshelves
are full of files ominously labeled "Jet Fuels," "Gulf
War," and "Chemical Warfare."
Monteiro-Riviere is based in the CVM's Center for Chemical Toxicology Research
and Pharmacokinetics, one of the country's top university centers focused on
drug delivery through the skin. Her work spotlights absorption of pesticides,
industrial chemicals, and pharmaceuticals, as well as the resulting physical
effects on the skin itself. The research has become increasingly important in
recent years in helping the U.S. military develop antidotes and treatments for
soldiers exposed to chemical warfare agents.
Monteiro-Riviere
has been getting under peoples skin as a researcher and
teacher at NC State since 1984. As an investigative dermatologist and toxicologist,
she uses in vitro models to mimic human skincell cultures, flow-through
diffusion cells, and flaps of pig skin (a system she and husband Dr. James
Riviere developed in 1984). Live pigs provide the most human-like in vivo model,
but Monteiro-Riviere is an advocate of replacing, reducing, and refining the
use of animals for research where possible. To that end, she leads a team including
technicians Al Inman and Lauren Gast in developing a new kind of artificial skin
with all the layers and internal structure of living human skin.
"Commercially available 3-D skin culture models have no homogeneous basement
membranes or complete barrierwhich we need for testing blistering agentsnor
do they have melanocytes, Merkel cells, Langerhans cells, dermis, or vascular
system," she explains. "And because the product lots vary greatly,
it is difficult to use them to reproduce results and standardize among laboratories,
let alone extrapolate to humans." Part of the reason lies in the techniques
used to culture the skin cells.

Working with industrial engineering professors Ola Harrysson and Denis Cormier
and textile chemist Marian McCord, Monteiro-Riviere has designed a biologically
and functionally complete skin organ system using advanced tissue engineering
techniques. The team has conducted a promising pilot test using piezo-electric "ink-jet" printer
technology to spray cells layer by layer onto novel thermo-reversible hydrogel
scaffolds to create an anatomically intact and fully functional epidermis and
dermis. This skin could be used in percutaneous (through the skin) absorption
research or as grafts for burn patients.
With some refinements since the pilot test, the printer is ready
again to start laying down cells in gels. "The control inherent to the ink-jet
technology, coupled with the use of optimized gels allowing incorporation of
appropriate substrates, lipids, and growth factors, should allow production of
a human-skin-equivalent system," says Monteiro-Riviere. "The ability
to mass-produce artificial skin will not only reduce or replace the use of
animal skin in research, but also make it easier to screen large numbers of
compounds,
including those toxic or lethal agents that we could not ethically study in
animals."
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