Wound dressing control and activation

Disclosed embodiments relate to a wound dressing which can generate nitric oxide. The wound dressing may include a cover layer, an activator layer such as an acid providing layer and nitric oxide source layer, such as a nitrite providing layer. The activator layer may include acidic groups and may be hydrogel, xerogel, or other suitable material. The nitric oxide source layer may include a nitrite salt. Nitrite ions of the nitric oxide source layer may react with the acidic groups of the activating layer to generate nitric oxide. The activating layer may include a window at the center, and a central absorbent material may be positioned at the window. Various separating layers may also be incorporated into the dressing to control the interaction between activating layer and nitric oxide source layer.