Biomedical Engineering Reference
In-Depth Information
caused by antibiotic-resistant organisms. Already, the increase in both chronic and
complex wounds has resulted in the proliferation of wound centers and hyperbaric
centers around the nation.
2
From a health economics standpoint, there is a desperate need for better cost-
effective technologies to stimulate healing and regeneration of the integument. To
date, very little public attention has aimed at treating wounds because in most
cases, they are not life threatening and the discussion of wounds in public is not
socially acceptable. As a result, most patients with wounds quietly hope they will
heal and rarely organize requests for additional governmental resources to be
directed towards these problems. Wound care in the USA is also fragmented by the
care provided by practitioners in multiple specialties including surgeons, internists,
podiatrists, nurses, therapists and others. As a result, no single professional
organization has a unified voice for wound care. For the foreseeable future, most
of the investment in improved wound care products will probably originate in
industry and is likely to be product focused. It is hoped that academic basic science
and clinical researchers can team up with industry to develop and test better
products for our patients in the future.
15.3
A more normal skin - regenerative response
Skin differs depending on the site, age and race of a particular patient. It is hoped
that in the future, we will have the design capability to match carefully the
intricacies of site-specific skin. For example, glabrous skin on the palm or soles has
a very different texture and feel than skin on the abdomen or back. Placing a skin
graft from the abdomen onto the palm of the hand gives a very unnatural
appearance and often causes chafing at the borders. Wood
et al.
3
reported using a
cell spray technique to deliver keratinocyte specific cells to glabrous recipient
sites.
Melanocytes can then interact with the keratinocytes providing melanin for
pigment deposition. It appears that cell spraying techniques may possibly be able
to correct pigment deficits.
4,5
The absence of hair follicles, sweat glands and
sebaceous glands also significantly decrease the function and appearance of skin.
As we understand more about the stem cells involved in each of these organelles,
future strategies may be identified that will accurately recapitulate these structures.
The use of composite tissue allografts may make some difficult facial and
extremity reconstructions possible with good results. The major problem with
these procedures is that skin is highly antigenic and use of allografts requires high
doses of immunosupression drugs. Nevertheless, as progress is made in tolerance
- better immunomodulatory drugs, or pre-treatment of the allograft - this techni-
cally demanding procedure may increase over time.
Reconstruction of the dermis will continue to challenge us for some time. Great
progress has been made with the introduction of scaffolds including human
cadaver skin, lyophilized human dermis and a variety of collagen-based matrices
that have been used with increasing frequency in burns and complex wound cases.
