In 1987, the ravages of Aids were
being taken increasingly seriously. Gilles Argy, head of R&D
at Hutchinson in France, visited a group factory making condoms,
accompanied by René-Guy Busnel, director of a research laboratory
on animal physiology (CNRS). Wouldn’t it be possible to develop
a double sheath, the two layers sealing in a disinfectant able to
destroy the Aids virus if the condom tears?' suggested Professor
Busnel. But it soon became clear that given the actual conditions
under which a condom is used – not to mention the possible
harmful effects of virucides on female sexual organs – this
type of prevention would be unworkable in practice. Replacing the
double layer with a single layer incorporating crushable microcapsules
containing the disinfectant seemed equally complex.
'The condom was not the right target, but an idea had been sown,'
explains Gilles Argy, who subsequently thought of a way of applying
the same principle to latex gloves used by surgeons and healthcare
staff. At the time, the medical world was growing increasingly concerned
at the risk of transmission of the HIV or hepatitis C viruses through
contact with the blood of contaminated patients. Injuries to the
hands caused by needles or bistoury blades soiled with blood are
not, in fact, rare. What’s more, latex does not provide 100%
protection as it becomes porous when stretched for long periods.
After a lengthy operation surgeons can find that their hands are
stained with blood even if their gloves appear intact.
However, crushable microcapsules were not seen as the ideal system.
It was not until 1995 that a better solution was found, when Andre
Cheymol, project leader at Hutchinson, and Gérard Riess,
a lecturer at the Mulhouse School of Chemistry, came up with the
idea of using an emulsion. The final concept was born: a kind of
'sandwich' glove consisting of two external layers made from an
elastic material with an intermediate layer containing the emulsified
disinfecting agent, in the form of uniformly distributed droplets.
When a dirty needle punctures the glove, the active agent mixes
with the biological liquid on the needle and the blood from the
There were two problems. First of all, a non-toxic, non-allergenic
disinfectant was needed which would be compatible with the latex
and destroy the virus very quickly. This product also had to encounter
every viral particle introduced. The choice was made by a process
of elimination. Among the known molecules, the best candidates were
quaternary ammoniums – tensioactive compounds widely used
for their disinfecting and detergent properties. They are remarkably
effective in dealing with enveloped viruses such as HIV or hepatitis
C, especially in the very particular conditions of an accidental
scratch or pricking involving very brief contact. 'We now use a
more all-purpose mixture with a wider spectrum of activity,' explains
The second problem was more delicate. An emulsion had to be found
which was sufficiently fluid for the virucide to be released during
the few milliseconds it takes the needle to puncture the glove.
It was calculated that the droplets needed to be an optimal average
of 30 micrometres diameter to be sure they would be perforated by
a needle. 'It was a student at Mulhouse, Pierre Hoerner –
now a project leader with us – who developed the emulsion,
and the equally difficult matter of how to incorporate it in the
glove, while working on his thesis,' explains Gilles Argy.
Ordinary surgical gloves are made by plunging moulds – in
the form of porcelain 'hands' – into an aqueous latex solution.
As water cannot be used in combination with ammoniums, organic solvents
had to be used in this case, with all the associated constraints.
A German chemicals company, Goldschmidt of Essen, produced the stabilising
product, in accordance with Professor Reiss' specifications.
The latex was also replaced by a thermoplastic elastomer, a synthetic
material which avoids the allergic reactions natural rubber seems
to be causing increasingly among healthcare staff. Once laboratory
studies had shown the project to be feasible, in 1996 Hutchinson
turned to the European Commission which agreed to finance wider
cross-border co-operation helping to launch a pilot production plant
under the Biomed 2 programme. Based at the production site of the
Hutchinson subsidiary Mapa in Liancourt, France, this unit can produce
400 000 pairs of gloves a year. If this innovation proves as successful
as is hoped, the next stage will be to move to genuine industrial-scale
production, with continuously automated production lines.
In the meantime, the glove has become a reality – thicker,
admittedly, than ordinary gloves, but made of a more supple material.
The first tests – for mechanical resistance, ergonomy, user
tolerance – took place in 2001. They were managed by Biomatech,
a company specialising in the preclinical and clinical evaluation
of medical devices, in co-operation with the Lyon Sud hospitals
in France where clinical trials were conducted in the autumn of
Jean-Louis Caillot, the surgeon who supervised these trials, reports
that 'the dozen specialists who tried them believe that freedom
of movement is no longer affected after just a few minutes adaptation.
The surgery took place in conditions close to those with a traditional
double-gloving.' Orthopaedic surgeons, who are familiar with this
system, 'got used to them a little quicker than some of their colleagues
who still only use a single pair of gloves'. Another advantage is
that during 'normal' use, that is without perforation, the protection
is perfectly impervious to bacteria and even viruses. More interesting
still, the layer of emulsion is a barrier which destroys or blocks
viruses which would try to penetrate if the glove were accidentally
punctured. As a result, however long the surgery lasts, the surgeon's
hands never come into contact with the pathogenic agents which may
be present in the patient's blood.
The next step? Before they can be made commercially available,
the gloves need the recognised EC mark required for all medical
devices – the procedure for this is already in progress. Also,
early in 2003, Professors Stanley Plotkin and Fernand Bricourt will
publish an article on the purely scientific aspect of the project
in the Journal of Medical Virology. 'This is essential to ensure
product credibility,' explains Gilles Argy. Apart from hospital
staff, Hutchinson believes that NGOs, emergency services and military
personnel operating in regions with a high viral risk could be potential
users of the glove.
Finally, it should be made clear that although this glove greatly
reduces the viral charge (by about a factor of 15), and thus the
likelihood of the transmission of a disease, it does not eliminate
it altogether in the event of an accident involving contact with
blood. Healthcare staff must, therefore, continue to remain vigilant
at all times.