Biomedical Engineering Reference
In-Depth Information
only a few selected applications below, growing, directing and interacting with
cells on chips has been one of the flourishing areas in the field of microfluidics
with many applications and several reviews.
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Microfluidic platforms allow the control and manipulation of the micro-
environment of different cell types using low reagent and sample volumes, and
achieving a level of specificity otherwise unachievable through traditional
culturing techniques. Advances in microfabrication methods, such as inte-
gration of valves, pumps, mixing modules and controlled flow channels allow
separation of the cell culture, control of culture media and fluidic exchange, as
well as adjustable mechanical design of barriers between the chambers
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and
directed growth patterns of neurons.
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The latest advances in surface chemistry,
electrochemistry and microtechnology can be combined to create smart, low-
cost and disposable devices, with spectacular applications in analyzing the
structure and function of single neurons or networks of neurons to understand
their activity and to elucidate mechanisms of memory and learning that may
lead to the understanding of physiological and pathological brain processes.
Microfluidic platforms can be used to culture cells in separate compartments
to conduct localized drug treatments. Such microcompartments can isolate
axons for studying axon degeneration/regeneration under multiple parallel
experimental conditions.
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Figure 3.16 composed of three PDMS layers
(a substrate layer, a compartment layer, and a culture media reservoir layer) is
an example of such microcompartments for neuron cultures.
Prior to compartmetalization and culturing, microfluidic devices can also be
used to isolate specific populations of cells derived from the nervous system.
Examples include high throughput and high purity neural cell sorting through
two-step separation by combining soft inertial microfluidics and pinched flow
fractionation.
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The concept of separation is illustrated in Figure 3.17. In this
application separation is achieved in two steps. The first involves soft inertial
microfluidics where cells experience a very high velocity gradient produced by
d
n
4
t
3
n
g
|
7
n
3
.
Figure 3.16
(A) Illustration of the assembled neuron culture platform device showing
cross-sections. (B) Close-up view of the axon compartment showing
culture media flow during the one-step culture media replenishing
process.
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(Reprinted by kind permission of the Royal Society of Chemistry.)
