Curative effect of porous silk fibroin scaffolds combined with chondroitinase ABC in treatment of spinal cord injury

Objective To investigate the effect of porous silk fibroin scaffolds (PSFSs) combined with chondroitinase ABC (ChABC)for treatment of rats with spinal cord injury (SCI).Methods After exposed to T9 spinal cord transection injury,96 SD rats were divided into control group,PSFSs group,ChABC group,and PSFSs plus ChABC group according to random number table.BBB scoring system was used to evaluate hindlimb motor function in rats.Immunohistochemistry and Western blot analysis were performed to detect expression levels of neurofilament-200 (NF-200),glial fibrillary acidic protein (GFAP),and growth associated protein-43 (GAP-43) of the injured spinal cord.Immuno-fluorescence staining was carried out to evaluate regeneration of nerve fiber.Results BBB score improved in PSFSs group (8.1 ± 0.8),ChABC group (9.0 ± 1.1),and PSFSs plus ChABC group (13.7 ± 1.3) compared with control group 4 weeks after injury (5.3 ±0.7,P ＜0.05).Immunohistochemistry showed higher integral absorbance (IA) values of NF-200 and GAP-43 in those treatment groups,but smaller GFAP-positive area was observed compared with control group (P ＜ 0.05).Immuno-fluorescence staining indicated more GAP-43 growth at injury sites in PSFSs plus ChABC group in contrast with other 3 groups.Western blotting showed levels of NF-200,GFAP,and GAP-43 differed among groups (P ＜ 0.05).Conclusion PSFSs combined with chondroitinase ABC transplantation can enhance axonal regeneration,inhibit glial scar proliferation and hence promote motor function recovery. Key words: Spinal cord injuries ;  Fibroins;  Stents;  Chondroitinase ABC