FIG. 11.

Immunohistochemical analysis of pericardium samples from an in vivo subcutaneous model. Cell populations in the region of the implanted tissues were stained for F4/80, a macrophage surface marker. Staining shows a correlation between dense cell regions and the F4/80 stain, indicating an inflammatory response. A dense line of macrophages is seen near the edge of the GA-treated tissue, while in the PPF reinforced and untreated samples, macrophages are seen in smaller regions throughout the sample. On the other hand, there was no significant F4/80 expression in day 0 samples (A) and samples lacking the primary antigen from week 6 (B). A rat spleen stained by the same procedure is shown in (C) as a positive control. Scale bars represent 100 μm.