This is a prospective study of participants with diabetic foot ulcers who will receive either maggot debridement therapy (MDT) or conventional dressing therapy (CDT). Wound healing time is the main outcome measure to compare the clinical efficacy of these two therapies. The investigators developed a hypothesis that MDT could achieve remarkable shorter time and better healing rate for wound closure when compared with CDT.

The investigators designed a prospective randomized study to compare the clinical safety and efficacy of maggot debridement therapy (MDT) and conventional dressing therapy (CDT). This study is scheduled from July 2016 to February 2017. Patients, aged from 18-80, who suffered from type 2 diabetic mellitus foot ulcers with Grade 1 or Grade 2 according to the Wagner classification could be the participants of this study. A sample of 138 participants was calculated based on the morbidity of diabetic foot ulcers, accounting for estimated 10% attrition rate. The glycemic control is important for the validity of study results. A specific team of endocrine doctors will manage the blood glucose of participants of two groups within the range of 7-10 mmol/L.

Participants will be allocated into MDT group and CDT group randomly according to the random number table. For MDT-participants, bio-bags containing sterilized, live, medicinal Lucilia sericata larvae will be placed on the wound of ulcers. For CDT-participants, conventional dressing (disinfected by iodophor, dressed by gauze ) will be performed ordinally. Every 3 days the procedures of two groups will be performed and wounds assessment will be done until the wounds closure is achieved. The wounds assessment, including measurement of the area of wound surface and bacterial culture, will be performed by a specific team of microsurgical doctors. The outcome measures include wound healing time (days) and the time negative bacterial culture occurs (days). The secondary outcome measures include the area of wound surface (cm2), treatment related pain, comfort of the dressing and adverse events.

Inclusion Criteria:

1. Participants aged from 18-80 years old.
2. Participants with type 2 diabetes mellitus longer than one year, foot ulcer longer than three weeks and with ischemic symptoms of lower limb.
3. The ulcer erosion depth is not reached and muscle layer.
4. The Wagner classification of ulcers should be Grade 1 or Grade 2.
5. Blood glucose control: Fasting blood glucose ≤ 8mmol / L; Postprandial blood glucose two hours ≤ 11.1 mmol / L.
6. Participants do not receive ulcer wound management in the past three days when recruited.
7. Participants with neuropathy symptoms, such as limb numbness, tingling or pain, especially pain at night.

Exclusion Criteria:

1. Participants with acute thrombosis that required thrombolysis or thrombectomy.
2. Participants with severe systemic infection.
3. Participants who are sensitive to pain.
4. Participants with bone/joint deformities of foot (eagle claw toes, hammer toes)