Embodiments of the present disclosure provide systems and devices for delivering gaseous Nitric Oxide (gNO) under therapeutic parameters to reduce infection in a subject. Certain embodiments include devices and systems for delivering pressurized gNO to reduce bioburden and promote healing in the wounds of subjects having various disease conditions, including skin and soft tissue infections (SSTIs) and osteomyelitis. In some embodiments, the present disclosure provides portable wound healing devices for delivering pressurized gNO to the site of a wound to treat various disease conditions in a subject. Other embodiments relate to systems and devices for delivering and for monitoring gaseous Nitric Oxide (gNO) under therapeutic parameters of use to treat a subject. In certain embodiment, the devices include a subject interface unit comprising sensors for detecting gNO pressure and/or gNO flow.