ABSTRACT
BACKGROUND:There is no clear understanding on the effects of subcutaneous fat and stem cels on wound healing. OBJECTIVE:To explore the therapeutic effects of skin composite prepared with adipose tissue-derived stem cels on skin defects. METHODS: Epidermal cels, fibroblasts, adipose tissue-derived stem cels as seed cels and bovine colagen gel as a scaffold were used to build a complex with a variety of cels. A 6-mm diameter circular skin defect was made on the both sides of the rat back. The right side as experimental side was implanted with an 8-mm diameter multilayer skin composite, and the left side (control side) was only treated with a simple dressing. RESULTS AND CONCLUSION: For the constructed multi-layer skin composite, the epidermal layer was continuously merged into the multi-layer, the fibroblasts evenly distributed in the corium layer, and lipid droplets existed in the fat layer in which the cels distributed uniformly. Cel aggregation was obviously observed at the junction of different layers. In the experimental side, the rate of wound healing, granulation tissue thickness, the thickness of dermis and the capilary density were significantly higher than those in the control side. Taken together, we can construct multilayer skin composites with a variety of cels as seed cels, such as epidermal cels, fibroblasts and adipose tissue-derived stem cels, and bovine colagen gel as a scaffold, which promote wound healing and increase the thickness of dermis.
ABSTRACT
BACKGROUND:Epidermal stem cels are the source of cels for repairing the skin and its appendages. To study differentiation and migration of epidermal stem cels is crucial for perfect healing. Objective: To investigate the effects of substance P in skin wound repair. METHODS:Thirty Wistar rats were randomized into groups of substance P, capsaicin and control (n=10 per group). After the establishment of skin defect models, exogenous neuropeptide substance P, capsaicin, and normal saline were daily injected at the wound for continuous 5 days. Skin thickness, skin wound area, BrdU-positive cels were detected in the three groups at different time after injection. Results and conclusions:No difference n the skin thickness was found in the three groups at 14 days after injection (P > 0.05), but with time, the epidermal thickness was reduced. At 42 days, the epidermal thickness was reduced remarkably in the substance P group and decreased certainly in the capsaicin group, but unchanged in the control group. The wound area of the substance P group was significantly lower than that in the control and capsaicin groups at 3, 5, 7 days after injection (P 0.05). The BrdU positive rates in the three groups were significantly different at 3, 5, 7, 12 days after injection: the substance P group > the control group > the capsaicin group (P < 0.05). These results show that substance P can promote epidermal cel proliferation and accelerate wound healing.