The main purpose of this test is to assess the umbilical cord mesenchymal stem cells (MSCs) UC between source sample sweat gland cells wound transplanted effectiveness and safety for the treatment of large area skin lesions of the subjects

Inclusion Criteria:

• Sign the informed consent form when the age of 18 and 60 years old or less or more men or women (not pregnancy) The burned area: 10-20% TBSA, can satisfy the self control Time: early for skin grafts For location: limbs, chest and back

Exclusion Criteria:

• Serious allergic constitution; Have influence on the speed of wound healing of chronic disease patients; According to the researcher's judgment, may endanger the safety of the subjects or scheme compliance of any chronic disease or severe disease, including cancer, severe heart disease, kidney disease, liver disease, respiratory disease, nerve diseases of the nervous system, blood system diseases, etc.; Clinical researchers or for other reasons can't cooperate with the doctors, and other information is not suitable for clinical study of patients.

Can not meet the requirement of the long-term follow-up of patients.