3
tions will also be created to enhance
the resolution of such imaging mo-
dalities as MRI and ultrasound. As a
result of these improvements, dis-
eases will be detectable earlier than
they are today.
Another area where nanotech-
nology will advance detection of
disease is in biosensors, which can
monitor patients who are at risk for
specific conditions. Such sensors
might monitor, for example, blood
chemistry or pressures. The sensors
would communicate with devices
outside the body to report results.
Cygnus is one biotech company
that is beginning to venture into this
area, albeit at a much larger scale.
Cygnus has developed an instru-
ment, referred to as the glucowatch,
capable of monitoring blood glucose
levels in individuals suffering from
diabetes. The glucowatch is about
the size of a wristwatch, and the
system provides frequent, automatic
and non-invasive glucose measure-
ments over a twelve-hour period.
The system is designed to supple-
ment current needle-stick measure-
ments. Although exotic in this day
and age, some time in this century
highly sophisticated, small, and in-
expensive sensors employing
nanotechnology will be available
and used routinely in many parts of
our lives to monitor more than just
our blood glucose levels.
Susceptibility testing is another
important area where nanotechnol-
ogy will make significant contribu-
tions. Systems that can rapidly proc-
ess patient samples and detect an
array of medically relevant signals
at high sensitivity and selectivity
will also be developed for the clini-
cal laboratory. Some of these tests
will be based on nucleic acids (DNA
or RNA) and will be used, for ex-
ample, to rapidly determine a pa-
tient's susceptibility to certain dis-
eases, or infections. Companies
such as
Caliper Technology and
Agilent Technologies, or
ACLARA Biosciences, who are
developing and marketing lab-on-a-
chip technologies capable of proc-
essing small amounts of patient
samples for analysis at the nucleic
acid or protein levels will be major
players in delivering instrumenta-
tion and analyses. Other biotechs
who focus on detecting alterations
in nucleic acid sequences with DNA
arrays that point toward disease sus-
ceptibility will also be important
players. These include companies
such as
Affymetrix, Nanogen and
Orchid BioSciences.
Improved implants
Artificial organs or organ-assist
devices require implantable materi-
als that are both compatible with the
biological environment and resilient
to the chemistry of that environ-
ment. Better materials and under-
standing of their interactions with
the body may lead to the creation of
implants that the body will not only
accept but will actually integrate
into its system. Nanometer-scale
surface modification offers the po-
tential for developing structures that
will allow scientists to control inter-
actions between materials and bio-
logical systems. For example, tita-
nium implants now used for ortho-
pedics tend to become encapsulated
with dense fibrous tissue. This tis-
sue creates an uneven stress distri-
bution at the implant-bone interface,
which can result in implant loosen-
ing and failure, and can even frac-
ture the adjacent bone. This occurs
frequently in total hip and knee re-
placements. By applying
"bioactive" thin (nanoparticle) coat-
ings on the surface of the implants,
it will be possible to bond the im-
plant more naturally to the adjoining
bone and to significantly improve
the implant lifetime. Future funda-
mental discoveries in nanoscience,
biology, chemistry and instrumenta-
tion will help overcome the chal-
lenges in design and will provide for
the development of novel biocom-
patible materials with broad bio-
medical applications.
Drug discovery and
development
The inability to rapidly screen,
BioTech Sage Report, May 2001
