Biomedical Engineering Reference
In-Depth Information
9
Enhancing skin epidermal stability
J. R. SHARPE N. R. JORDAN
Blond McIndoe Research Foundation, UK
L. J. CURRIE
Derriford Hospital, Plymouth, UK
and
Abstract:
Long term epidermal instability has been encountered in full
thickness cutaneous wounds treated with cultured epidermal autograft. Here
we examine how fibrin and hyaluronic acid matrices have been developed to
provide a means of delivering keratinocytes to the wound bed and to improve
epidermal stability. The physical and chemical properties of fibrin and
hyaluronic acid provide an environment suitable for the generation of a stable
and organised epidermis. Studies using such carrier matrices have demon-
strated that a stable epidermal repair can be achieved clinically when these
materials are used in combination with cultured keratinocytes.
Key words:
epidermis, fibrin, hyaluronic acid, laserskin
®
, keratinocyte.
9.1 Introduction
A variety of approaches have been explored to provide restoration of the epidermis
whilst reducing the need to use large amounts of autologous split thickness skin
graft. These include the use of allogeneic cadaver skin, cultured epithelial autograft
(CEA), sprayed autologous cultured keratinocytes and an array of materials
designed to restore the physical and biological function of normal epidermis. The
transplantation of cultured epithelial autografts and sub-confluent keratinocytes to
repopulate the wound with keratinocytes has achieved some clinical success.
However, long term epidermal instability has been encountered and modifications
to the existing technique have been sought by combining cell-based treatments
with biomaterials. A number of biomaterials have been used to deliver cultured
keratinocytes to the wound bed, in order to improve the handling of the trans-
planted material, the cellular organisation of the repair tissue and its long term
stability. This chapter examines how fibrin and hyaluronic acid matrices have been
developed to provide a means of delivering keratinocytes to the wound bed whilst
providing an environment suitable for the generation of a stable and organised
epidermis.
The 'gold standard' epidermal replacement is autologous split thickness skin
graft (STSG). However, limitations in donor site availability and the creation of a
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