NOS3 and diabetes mellitus: The most common complications associated with delayed wound healing in diabetes include: a reduction in chemotactic and phagocytic ability of neutrophils [66], decreased angiogenesis [67], decreased vasculogenesis [68], reduction in endothelial nitric oxide synthase (eNOS) activity [69], elevated levels of oxidative stress [70], reduced levels of substance P [71], decreased collagen formation and a reduced level of various growth factors.