3. The presence of diabetic neuropathic ulcers "malum perforans" not involving subcutis (Grade I according to Wagner) at plantar site of the foot diagnosed by ABI ≥0.8, without claudication, or TcPO2 >40 mmHg or doppler ultrasonography (at the discretion of the investigator) to exclude significant arterial diseases and critical limb ischemia, and a diabetic neuropathy test using a 128 Hz vibration tuning fork according to Rydel-Seiffer (as described by Guideline "Nationale Versorgungsleitlinie - Neuropathie bei Diabetes im Erwachsenenalter"). If the ABI is >1.3, an additional doppler ultrasonography must be performed to exclude a PAOD masked by media sclerosis;