ELECTRODES OF TOMORROW
Professor Jens Schouenborg of the Neuronano Research Center at the
University of Lund, Sweden, on nano- and micro-scaled electrodes for
groundbreaking research in neuroscience and clinical medicine
Pan European Networks: Science & Technology
06
158
PROFILE
W
ith the technology of tomorrow we hope to be able
to help the severely disabled – patients suffering
from paralysis or movement disorders, from
intractable depression, epilepsy or chronic pain.We work hard to
develop the next generation of devices often referred to as neural
interfaces – small electrodes implanted in the human brain or
spinal cord – equipped with wireless connections to external
electronics and computers, with the purpose of understanding
fundamental brain functions and restoring lost function by
recording from and stimulating the nervous system.
The Neuronano Research Center (NRC) is an inter-disciplinary
research centre at the Medical Faculty of Lund University, Sweden,
co-ordinated by Professor Jens Schouenborg.Within NRC,
researchers from four different faculties (medicine, technology,
science and the humanities) design the electrodes of tomorrow.
With a focus on developing biocompatible multichannel
electrodes, NRC is rapidly becoming one of the internationally
leading centres in the field.
By embedding the electrodes in a
dissolvable support matrix, the
problem of inserting ultra-thin
electrodes into the soft brain
tissue with preserved electrode
architecture has been solved.
The use of these new electrodes for the continuous monitoring and
stimulation of nerve cells under physiological conditions will
provide the researchers with enormous possibilities to understand
how the brain functions, for instance, during learning. It also
provides completely new possibilities to treat several severe
medical conditions such as drug resistant depression, chronic
pain, and a number of neurodegenerative disorders.
The nervous system will, for the foreseeable future, constitute one
of the great challenges of the scientific community and diseases
affecting the nervous system will continue to cause suffering for
individuals and substantial costs for society. This is particularly
true in view of the increase of neurodegenerative diseases,
chronic pain and depression in an ageing population worldwide.
Neurophysiology in combination with micro and nanotechnology
will be invaluable tools for clarifying fundamental questions about
brain function, and will contribute to the development of
treatment strategies in the battle against a wide range of
disorders of the nervous system.
Already today, so called Deep Brain Stimulation (DBS) is the most
successful treatment of the advanced stages of Parkinson’s
disease and new studies indicate that it will also be useful in
severely depressed patients. The use of spinal cord stimulators for
pain control is another promising clinical treatment. However,
current electrodes for clinical use are quite primitive (large size,
few channels) and suffer from low specificity, side effects, loss of
device function over time, and destruction of tissue, sometimes
leading to fatal consequences.
NRC is focused on developing electrodes that have the potential
of being implanted in humans and animals for many years. To
achieve this goal we pay special attention to elucidate how to
control and eventually eliminate the long-term tissue reactions to
the implants. These reactions normally lead to encapsulation of
the implants and loss of function. This knowledge has been
incorporated in our electrode development. So far, four types of
ultra-thin and flexible multichannel electrodes have been
developed: (1) a wire bundle construct (diameter of each wire 7-
12μm) with anchors near their respective tips; (2) a chip
electrode (10-12μm thick) built on a very thin layer of polymer
with lateral protrusions serving the dual role of electrodes and
anchors; (3) electrodes which are flexible in 3D; and (4) a
nanowire based electrode. The first generations of these
constructs have been tested
in vivo
with very promising results
regarding stability and type of neuronal elements that can be
recorded from.
The NRC electrodes are flexible and elastic and can be anchored
in the target tissue. By embedding the electrodes in a dissolvable
support matrix, the problem of inserting ultra-thin electrodes into
the soft brain tissue with preserved electrode architecture has
been solved. In addition, nanoparticles containing different drugs
(e.g. anti-inflammatory substances or analgesics) can be
incorporated in the dissolvable matrix. After the matrix is
dissolved, the electrodes are highly flexible and can thus follow
the constantly moving tissue leading to reduced tissue
inflammation. This is particularly important for electrodes that are
to be implanted in the brain stem, spinal cord and peripheral
nerves, locations that exhibit considerable movements.
To allow wireless communications with these electrode implants,
NRC develops technology for telemetry, including new and efficient
NEURODEGENERATIVE RESEARCH
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