(A–B) Representative CD31 staining (red) of graft cross section and quantification of staining for the (A) proximal graft and (B) distal graft. Blue = nuclei stained with DAPI; red = endothelial cells; and green = autofluorescence. Data expressed as mean ± SE, represents 4–5 sections at each region for each rat (n=6–7/treatment group), analysis via one-way ANOVA. *P < 0.05 versus ePTFE. Original magnification = x 2.5, quadrants = x 20. PG: proximal graft, DG: distal graft, ePTFE: extended polytetrafluroethylene, POC-ePTFE: poly(1,8 octamethylene citrate) ePTFE, atRA-ePTFE: all-trans retinoic acid-coated ePTFE, and atRA-POC-ePTFE: all-trans retinoic acid- poly(1,8 octamethylene citrate) ePTFE.