Fig. 6.

In vivo performance of plain PVA, unpatterned (UP) PVA-CDI-aF, and luminal patterning with 2 μm gratings (2 μG) PVA-CDI-aF grafts in rabbit carotid artery end-to-side anastomosis model. (a) Representative ultrasound images of blood flow inside the grafts before surgery, 2 weeks after surgery and 4 weeks after surgery. Measurement of flow velocity inside the grafts at (b) 2 weeks and (c) 4 weeks. No statistical significance was observed. (d) Representative immunofluorescence staining images of endothelial cells in the lumen of implanted grafts. Graft segments that were close to the proximal end, at mid-point, and close to the distal end were imaged and analyzed. Scale bar = 100 μm. Blue denotes nuclei, green denotes VE-cadherin, and orange denotes CD31. (e) Endothelial coverage percentage of patent grafts. Occluded grafts were excluded from the analysis. n = 3 for plain PVA and UP PVA-CDI-aF, n = 4 for 2 μG PVA-CDI-aF. *, ***, and **** indicate a significant difference using two-way ANOVA with p < 0.05, p < 0.001, and p < 0.0001, respectively. (f) Percentage of endothelialized grafts (higher than 50% endothelial cell coverage) at each position. (g) Representative hematoxylin and eosin (H&E) staining images of proximal and distal anastomoses. Scale bar = 500 μm. IH indicates intimal hyperplasia. (h) Stenosis percentage at proximal and distal anastomoses. n = 4 for plain PVA and UP PVA-CDI-aF, n = 5 for 2 μG PVA-CDI-aF, no significance was observed. (i) Representative Masson's trichrome staining images of the stenosis in proximal and distal anastomoses of plain PVA, unpatterned PVA-CDI-aF, and 2 μG PVA-CDI-aF grafts. Scale bar = 500 μm. IH indicates intimal hyperplasia. Blue denotes collagen and red denotes muscle fibers. (j) Quantification of percentage of collagen and muscle fiber in the stenosis. P and D indicated the percentage at the proximal and distal anastomosis, respectively. n = 4 for plain PVA and UP PVA-CDI-aF, n = 5 for 2 μG PVA-CDI-aF. No statistical significance was observed.