Electrocution Aids in skin Permiability.
Title: Electric pulses pour drugs through skin.
Author(s): Raloff, J.
Source: Science News; 11/20/93, Vol. 144 Issue 21, p327, 1/3p
Document Type: Article
Subject(s): SKIN -- Permeability
Abstract: States that researchers at the Massachusetts Institute
of Technology have come up with a unique approach for temporarily
increasing the permeability of the skin. Use of electric current;
Implications for the administration of drugs; Report in the November 15,
1993 issue of `Proceedings of the National Academy of Sciences'; More.
Full Text Word Count: 407
Accession Number: 9311237688
Database: Academic Search Premier
Section SCIENCE NEWS of the week
ELECTRIC PULSES POUR DRUGS THROUGH SKIN
The skin's outer surface - a layer of dead, flattened cells - provides a
barrier to microbes, chemicals, and other potentially toxic agents. But
at times physicians would like to breach that barrier, because
administering drugs through the skin potentially offers several
Now, researchers at the Massachusetts Institute of Technology have come
up with a novel approach for temporarily increasing the permeability of
skin. They administer a series of very short, up-to-100-volt pulses of
electric current. The resulting rearrangement of fatty layers in the
dead, outer skin appears to create temporary pores, or channels,
explains Robert Langer.
Using fluorescent dyes to represent drugs, Langer's team delivered
millisecond pulses of current every 5 seconds for an hour and monitored
the dyes' passage through skin. Some tests used skin from human
cadavers; others involved live rats. In the Nov. 15 PROCEEDINGS OF THE
NATIONAL ACADEMY OF SCIENCES, Langer's group reports that the technique,
electroporation, achieved a reversible, 1,000-fold increase in skin
The idea of using an electric current to pass drugs through the skin is
not new It forms the basis of iontophoresis - a process that "uses very
low voltages for very long periods to drive a charged molecule [such as
a drug] through a barrier," notes Langer. Electroporation, by contrast,
not only employs much higher voltages for far shorter periods of time,
but also works on the barrier - here, the skin - not on the drug.
Langer emphasizes that before the technique can find use in drug
delivery, many nagging questions must be answered, including how safe
and effective it would be for long-term use.
A lack of imaging data to confirm mechanistically what's happening to
the skin surface leaves open the question of whether Langer's team
achieved electroporation - at least in the classic sense - says Bruce M.
Chassy A microbiologist at the University of Illinois at
Urbana-Champaign, Chassy uses electroporation to move materials into
However, he adds, 'whether it's electroporation is not really important"
- as long as the technique delivers a drug without permanently damaging
the skin. Indeed, he described the new MIT results as "exciting.' In
fact, he said, it may possess as much potential to transport samples out
of the body - perhaps for noninvasive blood sampling-as it has to move
small samples inside.
By J. Raloff
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Source: Science News, 11/20/93, Vol. 144 Issue 21, p327, 1p