Glial Scar Formation And Functional Improvement After Transplantation Of Silk Fibroin Scaffold Into Spinal Cord Injury Rat

Objective: To observe the effect of silk fibroin (SF) scaffold after transplantation intothe spinal cord injury (SCI) rats and to evaluate the application prospects of the SF scaffoldas tissue engineering material in repairing SCI.Methods: After the cylindrical nerve scaffold with the pores called SF scaffold madeof silkworm was fabricated, the surface and the cross-section shape of the scaffold wereobserved by the scanning electron microscopy (SEM). Transected SCI rats in theexperimental group received the SF scaffold transplantation, the control group suffered thetransection operation only. BBB function score evaluation test was carried out every weekafter the operation. Hematoxylin-Eosin (HE) staining of objective spinal cord was done.Immunohistochemistry of glial fibrillary acidic protein (GFAP) and growth-associatedprotein-43(GAP-43) tests of spinal cord tissue were carried out, which were used foranalyzing the situation of astrocytes (AS) and neuron growth. Meanwhile, the westernblotting test was used for the quantitative detection of the proteins.Results: BBB score was significantly higher in the SF transplantation group than thecontrol group (P<0.05). There was no sign of inflammation found under the microscopeobservation after transplantation. Some nerve fibers were found in the sections of SFtransplantation group, which was not found in the control group. The expression of GFAPin the SF transplantation group was less than that in the control group, there was significantdifference between the two groups (P<0.05). The expression of GAP-43in the SFtransplantation group was more obvious than that in the control group, there wassignificant difference between the two groups (P<0.05). Western blotting results showedthat the expression of GFAP in the control group was more obvious than that in the SFtransplantation group (P<0.05), while the expression of GAP-43was more obvious in the SF transplantation group (P<0.05).Conclusions: SF scaffold transplantation can decrease the formation of glial scar afterSCI of rats, which can promote the nerve fibers regeneration indirectly. It is probable thatSF should have a certain application as the tissue engineering scaffold in repairing SCI.