Biomedical Engineering Reference
In-Depth Information
Table 1.1
Many of the early concepts of current skin substitutes were developed
at MIT during the late 1970s and 1980s
Investigator
Rheinwald, Green
4-6
Bell
7,8
Yannas, Burke
9,10
Concept
Cultured epithelium
Bilayer cultured
Biodegradable
graft
template
Clinical
Large burns
Chronic wounds
Burns and
application
reconstruction
Product
Epicell
Apligraf
Integra Regeneration
Template
Company
Genzyme
Organogenesis
Integra LifeSciences
Biosurgery
Despite great advances in burn care, the resulting severe scarring and deformity
continues to be one of the greatest challenges facing burn victims and their
families. Research in recent years has focused on methods to improve regeneration
while limiting scarring. The following monograph will review many of the current
technologies available to clinicians, highlight some treatments that are in early
development phases and point to areas of potential improvement for the future.
A thorough understanding of the biology of skin and its response to injury is
essential for designing skin substitutes (Table 1.2). For centuries man has under-
stood the important functions of skin in providing a barrier to bacteria and moisture
loss as well as a strong and elastic integument that drapes over complex surfaces.
Historically, physicians have turned first to biological membranes that have these
basic properties including cadaver skin, pigskin and amniotic membrane.
Xenografts, such as pigskin, showed good temporary coverage but the very high
antigenicity resulted in predictable failure over the long term. Human cadaver skin
works well as a temporary skin substitute but tends to reject between days 10 and
Table 1.2
Some ideal characteristics of skin substitutes
•
Bacterial barrier
•
Mechanical strength
•
Drapeability
•
Elasticity
•
Semi-permeable to oxygen and water
•
Non-toxic
•
Non-inflammatory
•
Non-immunogenic
•
Long-term function
•
Heal in response to injury
•
Pigment
•
Adnexal glands
•
Specialized epidermal structure (e.g. glabrous skin)
•
Available off the shelf
•
Low cost
