OBJECTIVE: To review the advance in materials of nerve conduit and Schwann cell transplantation for preparation of artificial nerve with tissue engineering technique. METHODS: Recent literatures about artificial nerve, nerve conduit and Schwann cell transplantation were extensively reviewed. RESULTS: Many biomaterials such as silicon, dacron, expanded polytetrafluoroethylene(ePTFE), polyester and chitin could be used as nerve conduits to repair nerve defect, the degradable biomaterials were better. The nerve conduit with intrinsic filaments could be used to bridge an extended gap in peripheral nerve. Purified and cultured Schwann cells were still bioactive. Axonal regeneration could be enhanced after implantation of Schwann cells into nerve conduit. CONCLUSION: The ideal artificial nerve is composed of three dimensional biodegradable nerve conduit and bioactive Schwann cells, Schwann cells can be distributed in nerve conduit just like Bünger’s band.
OBJECTIVE: To study the effects of Schwann cell cytoplasmic derived neurotrophic proteins (SDNF) on the regeneration of peripheral nerve in vivo. METHODS: Ninety adult SD rats were chosen as the experimental model of degenerated muscle graft with vascular implantation bridging the 10 mm length of right sciatic nerve. They were divided randomly into three groups, 30 SD rats in each groups. 25 microliters of 26 ku SDNF (50 micrograms/ml, group A), 58 ku SDNF (50 micrograms/ml, group B) and normal saline(group C) were injected respectively into the proximal, middle and distal part of the degenerated muscle grafts at operation, 7 and 14 days postoperatively. The motorial function recovery assessment was carried out every 15 days with the sciatic nerve function index(SFI) after 15 days to 6 months of operation. Histological and electrophysiological examination of regenerating nerve were made at 1, 3 and 6 months postoperatively. RESULTS: There were significant statistic differences between the both of experimental groups(group A and B) and control group(group C) in the respects of the histological, electrophysiological examination and SFI(P lt; 0.01). CONCLUSION: The 26 ku SDNF and 58 ku SNDF can improve the regeneration of the injured peripheral nerve in vivo.
Objective To investigate the feasibility of establishing the visualization models of intraneural microvessels of sciatic nerves in Sprague Dawley (SD) rats by systemic infusion of Evan’s blue (EB) or lead oxide and to compare the advantages and disadvantages. Methods Fifteen healthy adult SD rats of either gender, weighing 200-250 g, were randomly divided into traditional group (group A, n=5), fluorescence group (group B, n=5), and radiography group (group C, n=5). Ink, EB, and lead oxide, all mixed with gelatin solution, were injected in groups A, B, and C, respectively. After 2 hours of cryopreservation under 4°C, all sciatic nerves were harvested and observed through stereomicroscope to make sure the filling condition. The two-dimentional (2D) images were then collected via reflexion fluorescent microscope in group B and via micro-CT scan in group C. All images were imported into computer to establish three-dimentional (3D) reconstruction models by Mimics 15.0. Results All groups could show the outline of intraneural microvessels of sciatic nerves under stereomicroscope. Diameters of them were measured under fluorescent microscope, ranging from 10 µm to 30 µm. Both groups B and C could establish 3D reconstruction models from 2D images. These models could clearly reproduce the structure of microvessels. Conclusion Both EB and lead oxide can be used to establish 3D reconstruction models to observe structure of the intraneural vessels. However, EB has some disadvantages, such as predisposition to infiltration, grainy 2D images and time-consuming procedure; it is not suitable for researches of large specimen. Though 2D pictures from lead oxide have lower resolution than EB, it is easier to be manipulated and appropriate for experiments of large specimen.