Experimental Study On Rad Submandibular Gland Cell-Silk Fibroin-Chitosan In Vivo

ObjectiveTo evaluate the feasibility of the tissue engineered submandibular gland constructed in vivo based on submandibular gland cells and silk fibroin-chitosan (SFCS)MethodsSubmandibular gland cells were obtained and purified. The second generation cells labeled by 5'-BrdU were seeded on SFCS (5mm×5mm×5mm). Total 36 SD rats were randomly divided into two groups. Experimental group:submandibular gland cells seeded on SFCS was implanted beneath the skin on the back. Control group: SFCS was implanted beneath the skin on the back.At 3,7,14d post-implantation, implant sites were examined local and systemic responses. After paraffin embedding, serial sections 6 mm thick were cut and stained with either hematoxylin and eosin or brdu tissue stain for immunohistochemical studies and examined the responses of tissue. Scanning electron microscope was used to observe the growth behavior submandibular gland cells on SFCS scaffolds. We used image analysis system to count the number of CK8 positive cells per unit area in high power microscope. SPSS for windows 13.0 was used to analyze the results by ANOVA (α=0.05)ResultsGeneral observation:In experimental group, at the 3,7,14d after in vivo implantation, capsule formed in the surface of insert and thickened gradually. In control group, it is similar to experimental group at the he 3,7,14d after in vivo implantation but at the 14d after implantation the insert is not completely in shape.Histological observation:postoperative inflammatory reaction of either experimental group or control group is strong at 3d. In experimental group, the fibers of SFCS always regularity, submandibular gland cells proliferate on the SFCS scaffold fused to form unit at the 14d after implantation. In control group the fibers of SFCS scaffold arrangement became irregular at the 14d after operation.Immunohistochemical observation:The results of labelled cells were positive by immunohistochemical method at each time point. In CK8 immunohistochemical staining, the average number of positive cell in experimental group at 3d was (29.53±9.37), the average number of positive cell in experimental group at 7d was (67.70±13.39), the average number of positive cell in experimental group at 14d was (139.07±47.27), which had statistical significance with each other.Scanning electron microscope:The shape of the SFCS scaffold was mesh. At earlier, submandibular gland cells presence in disorder at attach to the SFCS. At the 14d submandibular gland cells proliferate on the SFCS scaffold and form functional unit.ConclusionSuch constructed tissue engineered submandibular gland based on submandibular gland cells and SFCS is promising.