Biomedical Engineering Reference
In-Depth Information
epithelial basement membrane technology, it is constructed without cross-linking
restrictions, unlike Permacol™, and is designed to be replaced by the host's
fibroblasts and native collagen. It is indicated for second-degree burns, pressure,
diabetic and venous ulcers, donor sites, and Moh's surgical wounds. It is not
intended for third degree burns. It is stored dry at room temperature and reconstitutes
easily in saline or water. TEI Biosciences does have other forms of Primatrix, for
use in orthopedic (Tissuemend™), neurologic (Durepair™), urologic (Xenform™)
and, as of October of 2007,
18
Surgimend™ for use in general, plastic and
reconstructive procedures. Case reports for the use of Surgimend™ and Pri-
matrix™, and a few studies involving Tissuemend™, do not appear unfavorable at
the moment.
19,20
Currently in the US FDA certification process is Matriderm
®
, a bovine dermal
matrix from a German company, Dr. Suwelack Skin and Health Care. Having been
released in Europe within the past few years and not studied in the United States,
Matriderm
®
is a porous, 0.5-2 mm thick membrane of bovine types I, II, and V
collagen in combination with elastin obtained from the bovine ligamentum nuchae
via hydrolysis. It is irradiated, is not manufactured with any collagen cross-linking
chemicals or preservatives and can be reconstituted in saline or Ringer's solution.
Human studies on punch biopsies indicate that the scaffold is degraded within six
weeks, allowing for a significant influx of fibroblasts and vascular elements.
21
It is
indicated for use in a single or two stage procedure. Skin grafts may be laid on the
scaffold immediately or in a delayed fashion.
22
Several European studies have shown that Matriderm® is promising as a dermal
substitute. One study, comparing split-thickness skin grafts to split-thickness skin
grafts on top of a Matriderm
®
bed for deep partial and full thickness burns
demonstrated no difference in graft survival, but did show increased elasticity with
Matriderm
®
based on the Vancouver burn skin score (VSS).
23
Another study
indicated no difference in split thickness skin graft take with Matriderm
®
, although
related less hospital cost and length of stay, in addition to fewer 'skin related
problems and decreased itching'.
24
An Austrian group evaluated Matriderm
®
for
use as a dermal substitute in ten patients with severe hand burns and found that in
a one stage procedure, there was a 97% graft take, with great pliability, range of
motion and lack of hypertrophic scars.
25
Porcine small intestine submucosa has been under investigation for over a
decade. Its commercial popularized forms are Surgisis™ and Oasis™ (Cook
Biotech Incorporated, West LaFayette, IN, USA). Derived from jejunum, porcine
small intestine submucosa is composed mainly of types I and III collagen. The
serosa, tunica muscularis and tunica mucosa are removed, leaving behind the
stratum compactum and muscularis mucosa of the tunica mucosa in conjuction
with the submucosa. The remaining product still contains glycosaminoglycans,
proteoglycans and glycoproteins. In addition, mediators such as transforming
growth factor
) and vascular endothelial growth factor (VEGF) are
maintained, allowing for more rapid epithelial influx and neovascularization.
26-29
β
(TGF-
β
