Biomedical Engineering Reference
In-Depth Information
and organs in the laboratory and to safely implant them into the
human body for the purposes of healing. The nanofibrous matrix's
platform technology develops “designer scaffolds” for the purposes
of regenerative medicine, depending on the fabrication technique
known as electrospinning. Biomedically, the electrospun nanofi-
brous matrix has been used in various desciplines like nanofiber
skin grafts, blood vessel (vascular and cardiac) grafts, ligaments
grafts, nerve grafts, skeletal muscle grafts, bone tissue grafts, artic-
ular cartilage tissue grafts, skin grafts, and biogenic molecule (drug,
DNA, protein, and enzyme) delivery.
12.3.1
Skin Grafts
The skin is the largest tissue in the body. It is a modified epithelial
tissue, with a keratinized layer of dead cells that provides a physi-
cal barrier to the outside world. Skin wounds normally heal by the
formation of epithelialized scar tissue rather than by regeneration
of full skin.
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Of the two layers of the skin, epidermis and dermis,
the epidermis has less capacity to heal; however, when large areas
of the epidermis need to be replaced, normal regeneration is lack-
ing.Further,thedermishasanenormouscapacitytoregenerate.The
scar tissue that forms in the absence of the dermis lacks the elas-
ticity, flexibility, and strength of the normal dermis.
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Consequently,
scartissuelimitsmovements,causespain,andiscosmeticallyunde-
sirable. Therefore, engineered skin tissue would be an excellent
alternative, not only to close a wound, but also to stimulate the
regeneration of the dermis. In the late '90s collaboration between
clinical scientists and materials scientists at She
eld in England
made the first big improvement on this technique—the develop-
ment of flexible synthetic surfaces on which keratinocytes could be
easily cultured
in vitro
. The synthetic support medium allows for
rapid culture, reducing waste, and makes the tissue very much eas-
ier to handle. The cultured keratinocytes plus the synthetic support
form a flexible dressing that can be applied directly to the wound
bed.Clinicalstudieshaveshownthatcellsmigratefromthedressing
to the wound and greatly accelerate healing rates, frequently result-
ing in complete remission for chronic ulcers that had resisted other
treatments. Alongwith collagen, several other natural and synthetic
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