Cf. He et al., Effects of chronic wound fluid on the bioactivity of platelet-derived growth factor in serum-free medium and its direct effect on fibroblast growth, WOUND R REG, 7(2), 1999, pp. 97-105
The fate of biologically active proteins applied to chronic wounds is almos
t totally unknown. Growth factors may be degraded by proteases, which are p
roduced by both inflammatory and skin cells and by resident bacteria. Howev
er, there has been little work on the effect of chronic wound fluid on the
activity of growth factors. A bioassay method has been chosen to examine th
e effect of incubation of platelet-derived growth factor with chronic wound
fluid from leg ulcers on the in vitro growth of human dermal fibroblasts.
Human dermal fibroblasts were cultured in serum-free medium, and a dose-res
ponse curve for proliferation in response to platelet-derived growth factor
was obtained. Wound fluid was collected under occlusive dressings from fiv
e patients with chronic leg ulcers. Platelet-derived growth factor was incu
bated with chronic wound fluid at 37 degrees C for 4 hours, and the reactio
ns arrested by snap freezing. The resultant solutions were tested for their
ability to promote fibroblast proliferation. A colorimetric assay was used
to monitor changes in the platelet-derived growth factor mitogenicity. The
results showed that, in our standard culture conditions, chronic wound flu
id always stimulated fibroblast proliferation, and, in most cases, incubati
on of platelet-derived growth factor with chronic wound fluid increased the
stimulation compared with that produced by platelet-derived growth factor
or chronic wound fluid alone.