| Background and Objectives: Ideal skin equivalent should have an ability to inhibit bacteria. We aim to evaluate antibacterial ability of the Composite Chitosan Artificial Skin both in vitro and in vivo, which will give some evidences for the use of Composite Chitosan Artificial Skin in the clinic therapy, especially for covering the infective wound and burn. Methods: 1. The culture of human fibroblast and keratinocyte;2. Fabrication of the Composite Chitosan Artificial Skin;3. Study for antibacterial ability of Composite Chitosan Artificial Skin in vitro: four kinds of bacteria including Staphylococcus aureus ATCC25923, Escherichia coli ATCC25922, Pseudomonas aeruginosa ATCC27853 and Candida albicans ATCC10231 are used in the experiment. Six agar plates are spread for every kind of bacteria, which are divided into trial group and control group. In trial group, 50 ul composite chitosan dermal equivalent is dropped to the agar plate, two samples for each plate. while composite collagen dermal equivalent act as control group. After the plates have been incubated in 35℃ for a night, the antibacterial rings of every group are measured. Finally, the data are analyzed using statistical method. 4. Study for antibacterial ability of Composite Chitosan Artificial Skin in vivo: 24 SD rats are divided into trial group, control group and blank control group evenly. every rat have two wounds in the back, After 105cfu Staphylococcus aureus have been dropped to the full-thickness excised wound in rats. In trial group, the Composite Chitosan Artificial Skins are sutured to the skin around the wound. while the composite collagen artificial skins are used in control group. Following data are observed:①the common condition of SD rat,including the appetite,weight and etc; ②the healing of wound; ③counting the amounts of bacteria in tissue under the crust; ④observing the histological character of the tissue around wound; ⑤Identifing the expression of actin in the tissue by immunohistochemical staining ,in order to observe the healing of wound. Results:1. The results for antibacterial ability of Composite Chitosan Artificial Skin in vitro:①composite chitosan dermal equivalent have the antibacterial ability for Staphylococcus aureus ATCC25923,the antibacterial ring is 30.70±1.23mm.It is larger than ring of composite collagen dermal equivalent,which is 28.67±0.91mm.The data have significance in statistical analysis.②composite chitosan dermal equivalent have the antibacterial ability for Escherichia coli ATCC25922,the antibacterial ring is 12.47±1.43mm.It is larger than ring of composite collagen dermal equivalent,which is 9.74±1.44mm.The data have significance in statistical analysis.③composite chitosan dermal equivalent have the antibacterial ability for Pseudomonas aeruginosa ATCC27853,the antibacterial ring is 10.42±2.89mm.but composite collagen dermal equivalent have no antibacterial rings.The data have significance in statistical analysis.④both composite chitosan dermal equivalent and composite collagen dermal equivalent have no antibacterial ability for Candida albicans ATCC10231.2. The result for antibacterial ability of Composite Chitosan Artificial Skin in vivo①all the rats of trial group and control group have normal common condition, while that of the blank control group is bad;②wound healing of rats in trial and control group is better than that of the rats in blank control group.③the average amounts of bacteria in tissue under the crust of trial group are (8.09±2.51)×104CFU/g,and that of control and blank control group are (5.91±2.51)×105 CFU/g and (5.55±2.18)×107 CFU/g respectively;④the tissue around wound in trial group have little inflammatory cell infiltration, and that of control group have a few of neutrophilic granulocytes and macrophages, while many inflammatory cells are infiltrated in the tissue of blank control group, as well as necrosis and exudation.⑤with actin immunohistochemical staining, the basal cell and fibroblast in the trial group have s...
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