Platelets

ALPHA GRANULES contain a number of proteins: fibrinogen, von Willebrand factor (vWF), factor V (FV), platelet factor 4 (PF4), platelet-derived growth factor (PGDF) and transforming growth factor-beta (TGF-β). These last three chemically attract white blood cells, smooth muscle cells and fibroblasts to the site of injury and contribute to the process of wound healing.