wound-healing-reading-chapters

SRPS Volume 10, Number 7, Part 1
and Russia, where it is called “biostimulation.” 154
Weak biostimulation excites physiologic processes
and results in increased cellular activity in wounded
skin. 155,156 The mechanism is believed to be the
stimulation of ascorbic acid uptake by cells, stimulation
of photoreceptors in the mitochondria, changes
in cellular ATP, and cell membrane stabilization. 157–
159
The common types of low-energy lasers used in
wound management are the helium-neon laser and
the gallium-arsenide (or infrared) lasers.
Lasers accelerate healing of ischemic, hypoxic,
and infected wounds, especially when combined
with hyperbaric oxygen treatments. 160 Low-energy
lasers promote epithelialization for wound closure 161
and better tissue healing. 162–169 Laser biostimulation
has different effects at different wavelengths, and
optimal treatment requires several applications at
various wavelengths.
LED. The treatment area for a laser is limited;
that is, large areas must be treated in a grid-like
pattern. In contrast, light-emitting diodes (LED) produce
multiple wavelengths (680, 730, and 880nm
simultaneously 159 or 670, 720, and 880nm 170 in large,
flat arrays to treat large wounds. NASA developed
LED based on their research on wound healing in a
weightless environment. Work done on space
shuttle missions, on the international space station,
and aboard submarines shows significant improvement
in wound healing with LED therapy alone or
in combination with hyperbaric oxygen treatment.
Growth Factors. McGrath 2 defines growth factors
as follows: “A polypeptide growth factor is an
agent promoting cell proliferation. . . . These proteins
also induce the migration of cells, and thus are
not only mitogens but are also chemoattractants
that recruit leukocytes and fibroblasts to the injured
area.” Of particular importance to wound healing
are the fibroblast growth factors (Table 2). 4 Their
effect on the repair process is illustrated in Figure 6.
Platelets contain growth factors that stimulate
angiogenesis, fibroplasia, and collagen production.
These are called platelet-derived wound healing
factors (PDWHF). 171 A beta-chain recombinant
c-sis homodimer of platelet-derived growth factor
(rPDGF-β) appears to have immunologic properties
similar to PDGF—ie, it stimulates fibroblast mitogenesis
and chemotaxis of PMNs, MONOs, and fibroblasts.
172 Both PDGF and rPDGF-β accelerate
wound healing by augmenting the inflammatory
response and the accumulation of granulation tissue.
Table 2
Growth Factor Signals at the Wound Site
(Reprinted with permission from Martin P: Wound healing—aiming for perfect skin regeneration. Science 276:75, 4 Apr 1997.)
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