Figure 2.

Cross-sectional scans of the acellular nerve grafts at 14 days post-operation.

(A) In the control group (Con), acellular nerve grafts alone were transplanted. In the test group (Test), acellular nerve grafts were transplanted and daily intraperitoneal injections of cartilage oligomeric matrix protein-angiopoietin-1 were performed. Sections 1, 2, and 3 were selected by systematic random sampling from the proximal to the distal ends of the nerve specimen. Two distinct patterns of revascularization were found: one in the epineurium (narrow arrows) and the other in the endoneurium (broad arrows). In section 1, there was no apparent difference between the two groups. In section 2, the number of microvessels in the test group was significantly higher than that in the Con group. In section 3, the signal from the contrast agent was obvious in the test group, but it was only minimally present in the Con group. Scale bars: 100 μm. (B) Quantification of vascularization at day 14 postoperatively. The vascular index = the total area of vascular development region/cross-sectional area of the nerves × 100%. Data are expressed as the mean ± SD (n = 6). One-way analysis of variance followed by the least significant difference post hoc test was used. **P < 0.01, vs. Con group. NS: Not significant.