ObjectiveTo prepare adipose-derived stem cells (ADSCs) and chitosan chloride (CSCl) gel complex to study the biocompatibility and the feasibility of repairing the wounds of deep partial thickness scald in rats. MethodsADSCs were prepared by enzymogen digestion and differential adherence method from the subcutaneous adipose tissue of SPF grade 6-week-old male Sprague Dawley (SD) rats. Temperature sensitive CSCl gel was prepared by mixing CSCl, β glycerol phosphate, and hydroxyethyl cellulose in 8∶2∶2.5 ratio. The proliferation of ADSCs was measured by cell counting kit 8 (CCK-8) assay and the survival of ADSCs was detected by the Live/Dead flurescent staining in vitro. A deep partial thickness burn animal model was made on the back of 72 SPF grade 6-week-old male SD rats by boiled water contact method and randomly divided into 3 groups (n=24). Group A was blank control group, group B was CSCl hydrogel group, group C was ADSCs/CSCl gel group. The wound closure rate at 3, 7, 14, 21 days was observed after operation. The number of inflammatory cells at 7 days and epidermal thickness at 21 days were observed by HE staining after operation. The angiogenesis at 7 days was evaluated by immunohistochemistry staining with CD31 expression. ResultsCSCl had a temperature sensitivity, at 4℃, the temperature-responsive hydrogel was liquid and became solid at 37℃. The CCK-8 assay and Live/Dead flurescent staining confirmed that ADSCs could grow and proliferate in the ADSCs/CSCl hydrogel complex. General observation showed the wound closure ratio in group C was superior to groups A and B after operation (P<0.05). HE staining showed that at 7 days after operation, the wound healing of the three groups entered fibrous proliferation stage. Collagen deposition and inflammatory cell infiltration were observed in the dermis of each group. The proportion of inflammatory cells in group C was significantly lower than that in groups A and B, and in group B than in group A (P<0.01). At 21 days after operation, the fibrous connective tissues of neoepithelium and dermis in groups B and C were arranged neatly, and fibroblasts and neocapillaries could be seen. In group A, neoepidermis could also be seen, but the fibrous connective tissues in dermis were arranged disorderly and sporadic capillaries could be seen. The thickness of neonatal epidermis in group C was significantly larger than that in groups A and B, and in group B than in group A (P<0.01). CD31 immunohistochemistry staining showed that the neovascularization could be seen in all groups. The number of neovascularization in group C was significantly higher than that in groups A and B, and in group B than in group A (P<0.05). ConclusionThe ADSCs/CSCl hydrogel complex has a good biocompatibility and possessed positive effects on promoting the deep partial thickness scald wound repairing in rats.
Objective To explore the therapeutic effect of recombinant human epidermal growth factor (rhEGF) for burn wounds of degree II in the elderly patients. Methods From February 2003 to October 2008, 80 patientes with burn wounds of degree II were treated and randomly divided into two groups (n=40). In treatment group, there were 24 males and 16 females with an average age of 70 years (60-86 years), including 20 cases of superficial II degree and 20 cases of deep II degree.Burn wounds were caused by flame in 23 cases, by hot l iquid in 16 cases, and by electricity in 1 case. The mean time from injury to hospital ization was (2.87 ± 2.57) hours. The wounds were treated with silver sulfadiazine (SD-Ag) and rhEGF. In control group, there were 18 males and 22 females with an average age of 69 years (61-83 years), including 19 cases of superficial II degree and 21 cases of deep II degree. Burn wounds were caused by flame in 23 cases, by hot l iquid in 14 cases, by electricity in 2 cases, and by chemistry in 1 case. The mean time from injury to hospital ization was (3.39 ± 3.33) hours. The wounds were treated with SD-Ag. The dressing was changed every day until wounds heal ing. There were no significant differences in general data between two groups (P gt; 0.05). Results Wound did not heal in 1 case (deep II degree) of treatment group and in 5 cases (deep II degree) of control group over 40 days and free skin graft was used to repair wound. One case (superficial II degree ) in control group gave up treatment. One case (deep II degree) died of pulmonary infection in treatment group. These cases were excluded and 72 cases were analysed. No other side reactions were observed in teatment group except for flash stabbing pain (4 cases) and pruritus (2 cases). Wound infection occurred in 5 cases of the control group and in 3 cases of the treatment group, and wound healed after symptomatic treatment. The heal ing time of burn wound was (14.30 ± 1.26) days (superficial II degree) and (26.11 ± 2.97) days (deep II degree) in the treatment group, was (16.22 ± 1.40) days (superficial II degree) and (29.13 ± 4.99) days (deep II degree) in control group, showing significant difference between two groups (P lt; 0.05). Conclusion Incombined treatment, rhEGF can promote the heal ing of burn wounds of degree II in the elderly patients.