Repair Of Buccal Mucosal Defects In Rats With Silk Fibroin Materials

Objective: Repair buccal mucosal defects of the rat with two different silk fibroin materials. Compare the effect from observing the rate of wound healing as well as the degree of local, systemic immune inflammatory response. The feasibility was investigated in repairing oral mucosa with silk fibroin materials.Methods: Ninety male SD rats were divided into 3 groups randomly. The model of A group was replicated by using polyporous silk fibroin scaffold to repair the of buccal mucosal defect(sdiameter of 10mm,N=30).The model of B group was replicated by using cross-linking silk fibroin film to repair the buccal mucosal defects(diameter of 10mm,N=30).The buccal mucosal defects model of C group was covered with vaselinegauze only.(diameter of 10mm,N=30).All wounds were observed by macrograph or under optical microscopy and measured by vernier caliperon on 5th,10th,15th and 20th day postoperatively. The biocompatibility was evaluated by assessing both local and systemic immune responses from the histology,immunohistochemistry and peripheral blood T lymphocyte subset testing. All the data were analyzed by SAS 8.1 software package.Results:â‘ There were no infection through the wound healing process. On the 5th day postoperatively,the wounds of the A group were covered with yellow membrane; the silk fibroin membrane covered on the defect of the B group was still visible; the wound of C group was slightly red and swollen. In 5 days after operation,the degree of the wound shrinkage is C>A>B; 5 to 10 days after operation is B>C and A.â‘¡Histology and immunohistochemistry method shows that: The density of the inflammatory cell of the C group is higher than the A group. Different from the C group , there is little heterophilgranulocyte infiltration on the silk fibroin materials. 10 days after the surgery, the wound of the three groups were partly covered by epithelial cell,and CK expression positive was tested; There are large rate ridges for new epidermis of the A group. After 30th days, the new epidermis of the A group was similar compare to the normal one, the silk fibroin scaffold was mostly degradated; for C group,the layer of the epidermis cells is not the same,there are a lot of inflammatory cell in the newly formed mucosa.â‘¢Using sphericity test analyzed the percentage of CD3+,CD4+,and CD8+T cell in the blood of the three groups on 10th,20th,and 30th day postoperatively,there were no difference (P>0.05).Conclusion:â‘ Silk fibroin materials can inhibit wound contraction and ameliorate scar constriction of the oral mucosa.â‘¡Silk fibroin can promote the growth of oral mucosal epithelial cell to improve wound healing.â‘¢Silk Fibroin materials caused lightly local and systemic immunological inflammatory response , which possessed good biocompatibility can be used as a kind of materials to repair the defect of the oral mucosa.â‘£Compared A and B silk materials,porous silk fibroin scaffold is better than complex physical crosslinking of the silk fibroin film in the repair of oral mucosa defect.