Biomedical Engineering Reference
In-Depth Information
affects the formation of a fibrous capsule around implants, the
inflammatory response at the tissue-implant interface, fibroblast
attachment, angiogenesis, and many other cellular processes, such
as cellular differentiation, DNA/RNA transcription, cell metabolism,
ECM production, and phenotypic expression.
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-
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Studies of the
interactions between surface topography and cells have encom-
passed a wide variety of cell types and substratum features, includ-
ingroughness,
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,
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microgrooves,
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,
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ridges,micropores,
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wells,and
nodes, which can influence cellular behaviors. In the following sec-
tions, we will focus on the cellular behavior, including cell adhesion,
alignment, infiltration, and differentiation, on electrospun nanofi-
brous scaffolds.
10.3.1
Cell Adhesion
The contact of cells on the substrate is mediated by cellular
components such as integrins, adhesive proteins, and the actin
cytoskeleton. Cell adhesion is a complex process involving phys-
ical interactions, chemical binding events, and biological signal-
ing processes. It plays a central role in the regulation of cellular
behaviors such as cell proliferation, differentiation during develop-
ment, and the modulation of cell migration in the injured region,
metastasis, and angiogenesis. Thus, cell adhesion has been one of
the critical criteria for evaluating the integration of implanted bio-
materials. The topography of the surface of a biomaterial can influ-
ence cell adhesion and proliferation, which further affects cellular
functions. The electrospinning process provides the opportunity to
fabricatetissue-engineeredscaffoldswithanano-scaledtopography
andhighporositysimilartonaturalECM.Thesenanofibersprovidea
suitable material and environment for tissue engineering since they
can beused to enhancecell adhesion andproliferation.
Focal adhesions of cells can be regulated by the topography
of biomaterials. Focal adhesion lies at the convergence of integrin
adhesion, signaling, and the actin cytoskeleton, and it is known to
control signaling complexes and integrin function. For instance, the
diameters of electrospun fibers can be controlled by varying the
fabrication parameters (Table 10.1). This provides different topo-
graphical cues. Figure 10.2 shows the cytoskeletal organization and
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