Effectiveness of Autologous Platelet Rich Plasma in the Treatment of Chronic Non-Healing Wounds

This is a multicenter randomized controlled trial, with a single-blind parallel design. 1,500 subjects are planned to enroll in the study. Each subject will be assigned to the treatments in random order. The stratified permuted block randomization method will be applied to the patient assignment. In addition to three study populations, i.e., DFU, VU and PU, and study centers, stratification will be based on one overall variable, (1) nutritional status (Low: Prealbumin \<12mg/d vs. moderate: Prealbumin \>= 12 mg/d) and one variable for each wound type. Diabetic food ulcer will be based on offloading (2a) (Specialty shoes vs. Total contact cast), pressure ulcer will be based on offloading (2b) (mattress vs. cushion), and venous leg ulcer will be based on compression (2c)(Low: \<10 mmHG vs. High: \>=30mmHG). Randomization will proceed within strata according to a permuted block scheme with a block size, or balancing interval, varying randomly between 2, 4 or 6. The primary endpoint will be evaluated by a blinded physician to avoid the bias. Total duration of each patient in the study is expected to be 20 weeks.