Abstract: BACKGROUND: The integrity and functionality of oral mucosa are of great biological significance for isolating external stimulus and resisting the invasion of pathogenic microorganisms. In recent years, concentrated growth factor and recombinant human epidermal growth factor have become two research hotspots in the field of soft tissue injury regeneration and repair.  
OBJECTIVE: To investigate the repair value of autogenous concentrated growth factor fibrin membrane combined with recombinant human epidermal growth factor active protein polypeptide complex for oral mucosa equivalent injury.  
METHODS: The autogenous concentrated growth factor and the autogenous concentrated growth factor fibrin membrane combined with recombinant human epidermal growth factor composite fibrin membrane were prepared respectively. Human gingival fibroblasts and human immortalized keratinocytes were cultured on concentrated growth factor fibrin membrane and concentrated growth factor + recombinant human epidermal growth factor fibrin membrane, respectively. The proliferation of cells on the membrane was compared by histological staining. The 24 BALB/c - nude mice were randomly divided into control group (group A ) and back reconstruction group (group B: blank operation; Group C: concentrated growth factor fibrin membrane was covered after operation; Group D: concentrated growth factor + recombinant human epidermal growth factor fibrin membrane was covered after operation). The effect of wound repair in each group was evaluated by histomorphology and immunology, and the tensile resistance of repaired tissue in each group was detected by biomechanics at the weekend of the third week.  
RESULTS AND CONCLUSION: (1) Hematoxylin-eosin staining, SP immunohistochemistry, and immunofluorescence showed that cell proliferation of human gingival fibroblasts and human immortalized keratinocytes on concentrated growth factor + recombinant human epidermal growth factor fibrin membrane was significantly higher than that on concentrated growth factor fibrin membrane. (2) Hematoxylin-eosin staining and Masson staining showed that in group B, the epidermal layer was basically healed; the thickness of the spinous cell layer was reduced; and the amount of collagen fibers was small and discontinuous; in group C, the keratinocyte layer, spinous cell layer, and basal cell layer had different degrees of thickening; the epithelial spikes were reduced; and the collagen fibers were thick and dense, surrounded by new blood vessels. Group D showed similar performance to group C, but the number of collagen fibers, fibroblasts and new blood vessels increased remarkably. (3) Repair tissue tensile stress peak was group A> group D > group C > group B (P < 0.05). (4) These findings indicate that compared with concentrated growth factor fibrin membrane, concentrated growth factor fibrin membrane combined with recombinant human epidermal growth factor active protein polypeptide complex can not only promote the attachment and proliferation of human gingival fibroblasts and human immortalized keratinocyte, but also promote the equivalent injury healing of oral mucosa, increase the collagen fiber content and tensile strength of the damaged area, and show better repair value. 

Key words: concentrated growth factor, recombinant human epidermal growth factor, oral mucosa equivalent injury, fibrin membrane, active protein peptides, repair