[Preparation of bioactive denatured acellular dermal matrix from burn mice riched in mice bone marrow mesenchymal stem cells].

Objective: To investigate the preparation of bioactive denatured acellular dermal matrix (DADM) from burn mice riched in mice bone marrow mesenchymal stem cells. Methods: Twelve BALB/c mice were collected and 20% total body surface area scalds (hereinafter referred to as burns) with deep partial thickness were inflicted on the back skin of each mouse. After removing epidermis, the burned skin were collected and divided into Triton X-100 group and elhylene diamine tetraacetic acid (EDTA) group according to the random number table, with 15 samples in each group. Samples in Triton X-100 group and EDTA group were respectively placed in mixture of 2.5 g/L Triton X-100 and 2.5 g/L trypsin solution and mixture of 0.2 g/L EDTA and 2.5 g/L trypsin solution for sustained vibration and elution for 24 hours to make mice DADM. The general appearance of DADM was observed. The structure and arrangement of collagen fibers of DADM were observed by scanning electron microscope and tissue structure of DADM were observed by fluorescence microscope. Bone marrow mesenchymal stem cells (BMSCs) from mice were transplanted in mice DADM in the two groups with concentration of 2×105 cells per well to prepare bioactive mice DADM. After cultured for 3 days, tissue structure of bioactive mice DADM was observed by hematoxylin and eosin staining, distribution and number of BMSCs of bioactive mice DADM were observed by immunofluorescence staining. Proliferation of BMSCs of bioactive mice DADM after cultured for 2 h, 1 d, 3 d, and 5 d was detected by cell count kit-8. Data were processed with analysis of variance for repeated measurement and t test. Results: (1) Mice DADM in the two groups were white in appearance with certain tenacity and elasticity. Mice DADM in the two groups maintained good three-dimensional porous network structure. Collagen fibers of mice DADM in EDTA group were with good continuity, and collagen fibers of mice DADM in Triton X-100 group were fractured in varying degrees. Mice DADM in the two groups were decellularized completely, and the collagen fibers were loose and arranged disorderly. The continuity of tissue structure of mice DADM in EDTA group was better than that of mice DADM in Triton X-100 group. (2) After cultured for 3 days, the BMSCs in bioactive mice DADM in the two groups were evenly distributed. The number of bioactive BMSCs in mice DADM in EDTA group was 37±7, which was significantly more than that of mice DADM in Triton X-100 group (25±8, t=0.128, P<0.05). The proliferation of bioactive BMSCs in mice DADM in Triton X-100 group and EDTA group was similar at 2 hours and on day 1 after cultured (t=1.292, 0.656, P>0.05). On 3, 5 days after cultured, the proliferation of bioactive BMSCs in mice DADM in EDTA group was significantly higher than that of mice DADM in Triton X-100 group (t=2.309, 14.128, P<0.05 or P<0.01). Conclusions: Mice DADM prepared by decellularization of EDTA has better three-dimensional porous network structure and good continuity of collagen fiber. The BMSCs in bioactive DADM from burn mice prepared by transplanting BMSCs are evenly distributed with large quantity and strong proliferative capacity, which has the potential to be good autologous dermal substitute.