Temporal profile of changes in wound cellular composition. (a) Total granulation tissue cell numbers increase over time with no difference between young and old male subjects prior to three months. Closer examination reveals that the inflammatory cell profiles for (b) neutrophils and (c) macrophages differ significantly at day 3 (D3) post-wounding. (d) Differential re-epithelialization is also apparent at this time-point (D3). (e,f) In contrast, fibroblast and blood vessel numbers are increased in wounds from elderly subjects at the three month (3Mo) time point. Note equivalent numbers of each cell type in young and old wounds at D7 (red highlight), the time-point chosen for this study. (g-j) Comparative images for total cell (hematoxylin and eosin; g), neutrophil (CD15; h) macrophage (CD68; i) and endothelial cell (VWF; j) immunostaining. The scale bar in (j) represents 50 μm (g), 20 μm (h), 35 μm (i), and 45 μm (j).