[Toxicity studies in vivo and in vitro for sheep skin 
acellular dermal matrix].

Objective: To detect the toxic reaction degree for sheep acellular dermal matrix (ADM) in vivo or vitro by using hemolytic, pyrogen and cell-cytotoxic reaction experiments, respectively.
 Methods: Leach liquor of cross-linked and non-cross-linked sheep ADMs were set for cross-linked group and non-cross-linked group, respectively, with a positive control group (10 mL sterile water for injection in test tube) and a negative control group (10 mL 0.9% sodium chloride solution in test tube). The supernatants were obtained from each group and were measured for the absorbance. The hemolysis degree was calculated; 16 New-Zealand rabbits were selected and then divided into 4 groups, A, B, C and D group. The leach liquor of cross-linked and non-cross-linked sheep ADMs were injected into bodies of the 6 New-Zealand rabbits in the A and B groups, and then the body temperatures were measured in every half hour after injection, 6 times in total. The value of highest temperature among 6 measurements minus the normal temperature was the fever degree for the body temperature. Based on these fever degree, the criterion of biological pyrogen reaction for sheep ADM pyrogen experiment was evaluated; the mice fibroblasts were collected during logarithmic phase and were cultured in the nutrient medium containing sheep ADM leach liquor with different density. The absorbance was measured to evaluate relative growth rate for fibroblast.
 Results: The hemolysis degree for the group A and B are less than 5%. The summary of fever degree for New-Zealand rabbits were lower than 1.8 ℃. MTT experiment showed that the toxicity of 10%-90% or 100% leach liquor nutrient medium with sheep ADM for the mice fibroblast is at level 1 or level 2. There was no significant difference between leach liquor of cross-linked and non-cross-linked sheep ADMs (P>0.05). The effects on relative growth rate for mice fibroblasts were minor. 
 Conclusion: The hemolytic and pyrogen reactions for the sheep ADMs embedded in New-Zealand rabbit were within the evaluation criterion, and the effects on vitality and growth rate for the fibroblast were not significant.