Tissue Engineering Muscle by Micropatterning for T Essay

This essay has a total of 835 words and 6 pages.

Tissue Engineering Muscle by Micropatterning for Therapeutic Transplantation

Tissue Engineering Muscle by Micropatterning for Therapeutic Transplantation

There is growing interest to treat patients with inherited or acquired muscular disorders
by transplantation of cells to the site of dysfunction to restore normal function. One
candidate cell source is skeletal muscle, which can be harvested from surrounding tissues
for cell culture before injecting into the site of dysfunction. However, this treatment
may not be practical because harvesting skeletal muscle may lead to significant muscle
loss and increased susceptibility to infection.

One effective way to develop the needed tissue is through tissue engineering. Tissue
engineering is the development of molecules, cells, tissues, or organs to replace or
support dysfunctional body parts. Myoblasts, which are muscle precursor cells, a form on
stem cells found in muscle, are a promising cell source for tissue engineering because
they play an active role in regenerating muscle due to injury. Normally quiescent,
myoblasts respond to muscle injury by rapidly proliferating and then differentiating,
which results in the fusion of neighboring myoblasts into myofibers. Myoblasts can be
easily cultured in vitro and are capable of forming muscle. Since myoblasts have the
potential to differentiate into muscle fibers, they show tremendous promise for developing
muscle tissue that can be used to for cell transplantation and tissue engineering. By
creating an effective means of engineering muscle tissue, clinicians can produce the
needed muscle and implant it as required at the site of dysfunction.

The potential of such techniques would warrant the raising of such questions as to why
such practices are not occurring regularly and why people today are still suffering from
various muscle disorders. The unfortunate truth remains that engineering muscle with
structural capabilities as natural muscle is still quite challenging. In vivo, muscle
consists of bundles of myotube muscle fibers, which are fused multi-nucleated cells, and
these muscle fibers contract synchronously. However, when myoblasts are grown in Petri
dishes in vitro, they grow and differentiate into multi-nucleated myofibers in random
alignment, which do not resemble natural muscle structure.

Fortunately, recent research has lent forth a couple methods in an attempt to overcome
these structural impairments. One of such potential methods is to regulate cell alignment
by micropatterning techniques such as microfluidic and micromolding patterning.
Microfluidic patterning makes use of a silicone wafer etched by photoresist to create
channels of specific widths. An inverse pattern to the wafer can be prepared using an
elastic material known as poly dimethyl siloxane (PDMS),which can then be placed onto a
glass substrate, through which a polymer solution can be microfluidically introduced. Once
the polymer solution is allowed to evaporate, the PDMS stamp can be removed, leaving
polymer channels formed on the glass surface. Similar to microfluidic patterning,
micromolding uses the PDMS stamp as a mold for the polymer solution, which when dried,
forms a thin film with patterned grooves.

Micropatterning has been used to effectively pattern myoblasts on silica surfaces, but
myotube formation on micropatterned biodegradable polymer films has yet to be
investigated. Therefore, the purpose of the project is to engineer muscle fibers in vitro,
which can be applied for therapeutic implantation. By culturing myoblasts on patterned and
non-patterned biodegradable substrates, it is possible that the patterned substrate will
enhance cell alignment and differentiation into myofibers. Restricting cell alignment
would increase the probability of physical interaction, which would enhance the formation
of myotubes and direct their alignment towards forming parallel myofibers. These parallel
myofibers would more closely resemble natural muscle, which consist of many muscle fibers
in parallel. Although his could be carried out on both glass as well as biodegradable PLCG
polymer films, the polymer substrate would be more clinically beneficial. The use of
micropatterned muscle fibers on biodegradable and biocompatible PLCG films for therapeutic
implantation is promising.

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