Fig. 8.

H&E staining of in vivo implants at 40X magnification. Representative tissue sections were photographed from 3, 7, and 14 day excisional wounds containing PUR scaffold alone (control) or scaffold containing 1.8μg PDGF-BB (sample). The scaffold is visible as a pale, acellular structure. At day 3, the interstices of the scaffold already contain a largely fibrinous matrix and an inflammatory infiltrate with both mononuclear cells and neutrophils. At day 7, the sample exhibits a notably higher proportion of spindle-shaped fibroblasts. At 14 days, both specimens show evidence of interstitial fibrous connective tissue, but it is more apparent and abundant, relative to the cellular component, in the treated group. The scaffold material is associated with giant cells that appear to be attempting to engulf the residual scaffold.