Figure 5.

Addition of COL6 in Matrigel improves structural and functional recovery of sciatic nerve defect.

(A) Longitudinal sections with silver staining show regenerated nerves in catheters. The M + C group had the most orderly nerve bundles. (B) Widths of axon bundles, measured and compared among different groups (n = 16 slices from five animals, *P = 0.0360, ****P < 0.0001, one-way analysis of variance followed by Tukey's multiple comparison tests). (C) The continuous lengths of the axon bundles, measured and compared among different groups (n = 16 slices from five animals, ****P < 0.0001, one-way analysis of variance followed by Tukey's multiple comparison tests). (D) A sciatic nerve cross-section shows the retrograde fluorescence tracing on the tibial nerve tract in the M + C group. The green dotted line marks the region of the tibial nerve tract, and the red dots indicate the fluorescence positive axons. (E) Accuracy of tibial nerve projection in the M + C and M + V groups (n = 5 animals, **P = 0.0014, Student's t-test). (F) After 8 weeks of regeneration, we measured the CMAP in the sciatic nerve in different groups. Panels show representative traces of CMAP in the E, M + V, and M + C groups. The amplitude of CMAP in the M + C group was larger than those in the other groups. The black trace on the left indicates CMAP recorded from a normal sciatic nerve. The histogram on the upper right shows the amplitude recovery of the injured sciatic nerve (n = 5 animals, ***P = 0.0005, ****P < 0.0001, one-way analysis of variance followed by Tukey's multiple comparison tests). The histogram on the lower right shows the motor nerve conduction velocity between the groups (n = 5 animals, ****P < 0.0001, one-way analysis of variance followed by Tukey's multiple comparison tests). (G) SFI of rats at different time points. Scale bars: 400 μm in A and D. CMAP: Compound muscle action potential; COL6: collagen VI; E: empty; M + C: Matrigel + COL6; M + V: Matrigel + Vehicle; SFI; sciatic nerve function index.