Safety and Exploratory Efficacy Study of Collagen Membrane With Mesenchymal Stem Cells in the Treatment of Skin Defects

Inclusion Criteria: * Age between 18 and 70, borh gender. * Patient able and willing to sign informed consent and comply with study procedures. * Women of childbearing potential must use birth control pills, barriers or abstinence and have a negative pregnancy test. * Deep partial or full thickness skin defect of at least 9 cm2 requiring surgical wound coverage due to: burn injury, diabetic foot ulcer or wounds caused by mechanical damage or iatrogenic injury. Exclusion Criteria: * Patient refusal. * Patient has a documented history of allergy or sensitivity to any of the animal products used in preparation of skin substitute. These products include bovine blood, bovine collagen, and bovine collagenase. * Patient has a documented history of allergy or sensitivity to any of the antimicrobials or reagents used in preparation and application of skin substitute including the irrigation solution used before and after grafting. * Patient has a current diagnosis of an invasive burn wound infection in unexcised burn wound. * Patient has tunnels or sinus tracts that cannot be completely debrided. * Serious primary diseases of the liver, kidney and hematopoietic system, Abnormal liver function(glutamic-pyruvic transaminase(ALT), glutamicoxalacetic transaminase (AST) is 2 times higher than the normal value), creatinine(Cr) is higher than the upper limit of the normal value. * Other clinical trial participants within 3 months. * A random blood sugar reading \>/=450 mg/dL. * Investigators judge other conditions not suitable for inclusion.