Among the potentially HARMFUL
each template. A solvent then dissolves
the templates, leaving a material mottled
substances that MIPs have detected with plastic-coated cavities that have a
“memory” for the contours and charge
distributions of chemical groups in the
in tests is the herbicide ATRAZINE. original biological molecule.
The plastic imprints, named molecu-
But the original netting tool repre-
zymes and cells, I started to ask what larly imprinted polymers— or, as I
sents just a first attempt at devising might happen if we modifi ed our origi-
dubbed them, MIPs—have several at-
technologies that marry plastics and nal “fi shing” technology so that the net-
tractive features. They are inexpensive,
molecules. Today more than 500 re-
ting molded itself around the molecules
because they require relatively little time
searchers around the world are testing
it captured in a way that let us fl ush the
to produce and because the plastic
applications of a second technology, catches from the nets, leaving perma-
monomers are cheap. And, much like
molecular imprinting, which I played a
nent cavities, or imprints. Would these
their forebears, they can be stable for a
critical role in developing. My group de-
imprints enable other molecules of the
long time, even under extreme condi-
vised a now popular version using prin-
same type as the originals to fi t into
tions. Some of the preparations in our
ciples of biochemistry. Other investiga-
those holes? If so, I realized, the im-
lab have remained functional for as long
tors—notably Günter Wulff of Hein-
prints might be useful for various tasks, as a year.
rich-Heine University in Düsseldorf, including isolating selected molecules
One of the many potential uses for
Germany, and Kenneth J. Shea of the
from mixtures of compounds (because
MIPs is the removal of unwanted sub-
University of California, Irvine—devel-
only those molecules having the right stances from blood. Imprints of the sub-
oped methods based on principles of or-
shape and chemical groups would settle
stances in question would be displayed
ganic chemistry.
snugly into the cavities).
on plastic beads packed in tubes. A pa-
In general, plastic beads or other
For more than 20 years, my team in-
tient with, say, failed kidneys could rely
structures are covered with imprints of
termittently carried out experiments to
on one tube, or multiple tubes gathered
specifi c molecules, and the imprints—re-
develop this second technology. We did
together, in a device kept outside his or
ally, casts of the molecules—are put to what I call “moonshine research,” be-
her body to clear a dangerous substance
use for selected jobs. Once perfected, cause we had to prove the principle be-
from the blood system. As the person’s
this technology could have applications
hind the idea on our own, without for-
blood passed through an intravenous
in many areas, including the food indus-
mal funding. During that time, I heard
tube running between a vein and the ex-
try, which sees benefi t in its ability to unofficially that potential financiers terior MIP tubing, the beads would col-remove contaminants, such as the fun-
thought my notion seemed too far-
lect the selected substance, and the
gal poison afl atoxin. The new tools have
fetched, too much like magic.
cleansed fl uid would then reenter the
also begun to draw much interest from
Over the decades we fi gured out ways
circulation. Used at all times, such treat-
the biomedical fi eld, where they could
to make plastic imprints of molecules, ment could, in theory, reduce the fre-
speed the early stages of drug discovery
and outside funds started coming in. We
quency of needed hemodialysis. On be-
(bringing down costs), be used for drug
also managed to keep the procedure sim-
ing fi lled with the unwanted matter, the
purification and separation, and con-
ple; it takes only a few days to make MIP unit could be removed and replaced
tribute to the development of medical beads or thin films with hundreds of by another one.
devices and diagnostic tools.
thousands of imprints. First, a technician
Imprinted devices might eventually
mixes molecules of interest—what we be designed to pull unwanted substanc-
Moonshine Research
call templates—with selected building es from other body parts as well, such
a s m y l a b o r a t o r y at Lund was
blocks of plastics. These units, also called
as the gastrointestinal tract. Imprints of
studying methods to immobilize en-
monomers, create a plastic web around
cholesterol molecules, for example, can
extract cholesterol from solutions.
The selectivity of MIPs could also be
Overview/ Nanoplastic Applications
)
exploited by the pharmaceutical indus-
pagesg
■ Plastic imprints of specifi c molecules—molecularly imprinted polymers
try to make purer drugs. Such purity
n
(MIPs)—will capture those molecules and only those molecules. MIPs can thus
can become especially important when
ecedi
be used to separate desired substances from an impure mixture or to detect
a drug molecule occurs in two mirror-
pr ( xf
pathogens or toxins in the environment or in blood samples.
image forms, one of which is helpful
a