Evaluation of slow-release Tb4 collagen and chitosan porous sponge scaffolds skin substitutes the effectiveness of clinical trials for the treatment of difficult to heal wounds and security.

Inclusion Criteria:

1. Meet difficult had 1 month or more to heal the wound patients
2. Who signed the informed consent of men or women older than 17 (pregnancy)
3. Has the ability to care for, has the ability to self signed informed consent, 7 to 17 years old must be signed by the guardian informed consent
4. The process of mental stability, can finish the test

Exclusion Criteria:

1. Known allergic to bovine collagen or gao min physique
2. the wound is greater than the10cm×10cm
3. People with mental illness, drug abusers and or other items
4. Pregnant women,Prepare a pregnancy or breast feeding women 5.3 months participated in other similar experiment

6.Serious infectious disease not controller 7.With surgery, such as severe trauma stress situation 8.Can not meet the requirement of the long-term follow-up of patients