Biomedical Engineering Reference
In-Depth Information
Fig. 5.7
View of the dermis near the dermoepidermal
junction synthesized during repair and regeneration.
To p
:
Normal skin has a dermoepidermal region characterized
by complex undulations (rete ridges) and by the presence
of blood vessels (
v
) in the subepidermal region.
Middle
:
Scar is characterized by a flat dermoepidermal junction,
indicative of absence of rete ridges, as well as absence
of blood vessels in the subepidermal region.
Bottom
:
Regenerated skin shows dermal papillae containing
capillary loops that communicate with an underlying
plexus of well-developed blood vessels (
v
).
Bar
: 50 µm.
(Source: Yannas et al. 1989)
normal dermis, with well-defined papillae, normal anastomosing superficial vas-
culature, nerve fibers, and random collagen fiber morphology. Ungrafted sites at
1 year resembled a mature scar, with a flattened dermal-epidermal interface, rare,
and disorganized vessels and nerves and collagen fibers parallel to the epidermis
(Murphy et al. 1990).
The temporal appearance of various tissue components when DRT was seeded
with KC and applied to full-thickness skin defects in a porcine model was studied
during the period between days 4 and 35 after grafting (Compton et al. 1998). The
epidermis formed from clonal growth of individual KCs into epithelial cords and
islands that gradually enlarged, coalesced and differentiated to form large horn cysts
and eventually form a fully differentiated, normally oriented epidermis with rete
