• Measurement and characterization of stimulation of the wound's edges treated with the bioengineered skin construct (BSC) [ Time Frame: Measured throughout the study till Week 48 ] [ Designated as safety issue: No ]
  

• Response of BSC to injury, including meshed (wounded) and unmeshed BSC [ Time Frame: Measured throughout the study till Week 48 ] [ Designated as safety issue: No ]
  
• Activation of certain critical cytokines, including IL-1 alpha, IL-6, and TGF-beta [ Time Frame: Measured throughout the study till Week 48 ] [ Designated as safety issue: No ]
  

BSC is a two-layered sheet made from purified beef tendon collagen, living human cells, and a substance that maintains the cells until they are grafted (removed). We will obtain human cells from donors unrelated to the patient. The human cells have been tested for the presence of infectious agents and found to be free of disease-causing organisms such as hepatitis virus, the AIDS virus, bacteria, and fungi.

We will randomly assign (randomize) study participants to either the bioengineered skin group or control group (compression therapy with a multilayered compression bandage). Regardless of the group to which a patient is assigned, we expect participation in this study for 12 months following the start of study treatment. We will examine each patient at the screening visit (2 weeks before randomization) and then again 3-4 days before the start of treatment to make sure the wound is free of any signs of infection. After the initial randomization visit we will examine the wound once a week for 24 weeks or until the wound heals, whichever is earlier. As soon as we have determined that the wound is completely healed, we will ask the patient to return once a month for 6 months to make sure it remains healed.

Bioengineered skin group: We will apply BSC to the wound and cover it with xeroform dressing, foam bolster, gauze dressing, and compression bandage. If we do not note any improvement at the week 6 visit, we will apply BSC on the wound a second time.

Control group: We will place a multilayered compression bandage on the wound of participants assigned to this group.

Biopsies (small piece of skin tissue): At day 0 a biopsy will be taken from the thigh and leg ulcer. The biopsy from the thigh will require sutures and will be removed in ten days. Sometime between weeks 1 and 3, week 6, week 24 and week 48 (6 month follow-up) visits a biopsy will be taken from the ulcer (wound) if the ulcer has not healed. If the ulcer is healed at the week 48 visit, a light scraping of the healed wound will be performed.

Study examinations: All study examinations will include observation, measurement, and photography.

We can only admit women of childbearing age to the study if they are not breast feeding, not pregnant, or have been surgically sterilized or are using effective birth control. Because the effects of the proposed treatments on a fetus are unknown, we will remove from the study any woman who becomes pregnant while receiving BSC applications (day 0-week 3) and suggest another method of treatment.