The aim of this study is to evaluate the chance of non-healing diabetic foot ulcers repair by improving the condition of lack of oxygen or hypoxia in the wound area caused by diabetes using methylene blue along with the use of platelet-rich plasma-fibrin glue as an effective treatment for wound healing.

The current study assesses the effects of methylene blue along with the use of platelet-rich plasma-fibrin glue on wound healing in patients with nonhealing diabetic foot ulcers (non-healing DFU). This randomized controlled trial is performed on 20 patients with non-healing DFU. Patients were treated with PRP-FG dressing plus 200 ml of oral methylene blue dissolved in milk(intervention group) or PRP-FG dressing plus placebo (200 ml of milk) (control group) for 4 weeks.

Inclusion Criteria:

• Having a Diabetic ulcer grade II and IV based on Wagner's classification on the sole, medial, or lateral part of the foot (including all surfaces of the toes)
• Having a single ulcer on the feet and extremities (toes, soles, heels) with no significant reduction in ulcer size (<20%) despite the use of best treatment methods for at least four weeks
• If there is more than one non-healing wound, choose the largest wound
• The size of the wound surface (length × width) between 2 cm2 and 20 cm2
• No smoking, alcohol, and drug addiction based on the patient's self-report
• Not taking drugs that may interfere with wound healing, such as Corticosteroids, immunosuppressants, and cytotoxic agents
• Not having a concurrent chronic disease that may cause problems in wound healing, such as cancers, vasculitis, no history of known severe kidney, liver, and heart disease, such as liver cirrhosis, active hepatitis, dialysis, etc.
• Not taking antidepressants
• Insensitivity to milk lactose
• Not having Glucose 6-phosphate dehydrogenase (G6PD) deficiency
• Confirmed, informed, signed consent form
• Ankle Brachial Index (ABI) higher than or equal to 0.7

Exclusion Criteria:

• Do not be treated with methylene blue
• The confirmed presence of osteomyelitis, or if there is suspicion of osteomyelitis
• The subject is pregnant or intends to become pregnant during the test period
• The patient is known to have mental, developmental, physical, and emotional disorders
• The occurrence of certain medical conditions
• The presence of a wound with a clear and severe infection, which is characterized by significant purulent secretions or extensive cellulitis, or gangrene requiring amputation
• Evidence of venous, ischemic, neurotrophic ulcers (numbness, tingling, lack of Achilles tendon reflex) and traumatic wounds in the patient
• Failure to refer the patient more than two times to the mentioned center for follow-up and dressing change
• Hypersensitivity reaction to methylene blue
• Platelet count less than 100,000
• The patient's lack of consent to continue cooperation

All data related to the project after the unidentifiable people will be shared.

Access to data is allowed 6 months after the publication of results.

The investigator's data will be available to university staff and academic institutions.