This is a 10-week, randomized, controlled study to evaluate the efficacy and safety of the APT001 plasma and nitric oxide treatment in subjects with a diabetic foot ulcer.

Approximately 80 subjects will be randomized by computer to receive equally either sham therapy or plasma / nitric oxide treatments topically. The nitric oxide / plasma treatment will be delivered from 11.5 to 15 centimeters from the wound surface for 10 seconds per cm2 of wound size. Subjects will be evaluated for efficacy and safety on a regular basis with clinical observations. The wounds of both groups will be treated with sharp debridement as determined by the site Investigator. A collagen dressing, a non-adherent dressing, and an absorptive dressing will be applied to the wound after either the study therapy or the sham therapy.

For an initial safety evaluation in patients with DFU, the first ten patients randomized will be limited to wound size of 7 cm2 or less and their wounds will be assessed 2-4 days after each treatment session. Following completion of the final assessment in these 10 patients, data will be submitted to FDA for review and approval before opening the enrolment for the remaining patients.

Inclusion Criteria:

• 19 to 80 years of age
• Type 1 or 2 diabetes with hemoglobin A1c less than 12%
• ABI ≥ 0.7, palpable pulses and/or biphasic waveform study with Doppler
• Wound size ≥ 1cm2 and ≤ 30cm2 (the first 10 patients enrolled will be limited to a wound size of 7 cm2 or less)

Exclusion Criteria:

• Have a significant concomitant illness that would adversely affect participation in the study or affect the healing of the wound
• Have a severe infection in the ulcer including the presence of an abscess, cellulitis extending > 2 cm beyond the ulcer margin, or osteomyelitis
• Have involvement of deeper tissues including bone or tendon
• Be currently receiving steroid medications, chemotherapy, or other medications that might affect healing of the wound
• Have received topical or systemic antimicrobial therapy within 48 hours of screening
• Have a malignancy other than skin cancer currently being treated
• Have substance abuse issues within the 6 months prior to screening
• Is a woman who is pregnant or breast feeding
• Has been treated with another investigational product within 30 days of screening
• Has been treated with tissue engineered skin or a biological therapy within 30 days of screening