Study About External Use Of GM-CSF Gel In Improving The Success Rate Of Acellular Porcine Skin Covered Microskin Transplantation

Objective:To observe whether the external use of recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) gel can promote the wound vascularization and epithelization in microskin transplantation, so as to raise the success rate of acellular porcine skin covered microskin transplantation, prolong the time of protection and improve the wound healing quality in clinic by the acellular porcine skin, thus exploiting broad prospects for research and application of acellular porcine skin and rhGM-CSF.Methods:Part A (animal experiment):18rabbits were randomly divided into three groups, and full-thickness skins of them were cut off from both backsides (about5cmx5cm) and divided into the experimental group and the control group randomly.1/10of the removed skin was cut into microskin and replanted in the wound, and the acellular porcine skins that were coated with recombinant human rhGM-CSF gel were applied on rabbits of the experimental group; acellular porcine skins were applied on the control group, and then packaged and fixed. The three groups were unpacked respectively1,2and3weeks after the operation to observe the appearance and wound healing status, while tissues were taken from symmetrical parts for HE staining and immunohistochemical detection of PCNA and CDS1to assess the healing status. Part B (clinical trial):seven patients with Ⅲ°burn in both lower limbs were selected and numbered according to the admission sequential (self-control), and the bilateral lower limb wounds were randomly divided into the trial group and the control group. After the wound scab was cut off, the auto-microskin was transplanted to the wound by1:10(donating area:receiving area); acellular porcine skin coated with recombinant human rhGM-CSF gel were applied on the trial group, and acellular porcine skin were applied on the control group. After the edges were fixed, both lower limbs were wrapped with gentamicin saline gauzes and then gauze and cotton pad (conventional compression). After the operation, observe the drying and falling off time of the acellular porcine skin, as well as the wound healing rate after the acellular porcine skin fall off completely.Results:Part A (animal experiment):in the first week after operation, epithelization of the experimental wound was significantly more than that of the control group; in the second week after operation, wound healing rate of the experimental group was higher than that of the control group (p<0.01); in the third week after operation, wounds of the experimental group were basically healed, while residual wounds in the control group remained, showing significant difference between the two (p<0.01); According to the immunohistochemical detection of PCNA and CD31, the experimental group has higher CD31microvascular density (MVD) than the control group (p<0.01); positive rate of PCNA expression in the experimental group was apparently higher than that in the control group (p<0.01) in the first week; and the difference of positive rate of PCNA expression in healed tissues between two groups had no statistical significance in the first and the second week (p>0.05), in the unhealed tissues, the experimental group was higher than the control group (p<0.01). Part B (clinical trial):the trial group was later than the control group in dewatering and drying of acellular pigskin. Acellular porcine skin started falling off in batches at25.29±1.89d for the experimental group, and at24.86±2.19d for the control group, and the two had no statistical difference (p>0.05); wound healing rate after the acellular porcine skin fell off completely was81.17±3.43%in the trial group and70.50±3.33%in the control group, the difference was statistically significant (p<0.01).Conclusions:The experimental group:by external use of rhGM-CSF gel, neovascularization and epithelization of wounds were promoted, the success rate of microskin transplantation was raised, and the healing rate was increased; the clinical trial group:by external use of rhGM-CSF gel, the wound healing rate after microskin transplantation was significantly improved.