Luminal patency and laminar flow were similar between TEVG and native aorta over the course of the 12 month experiment.

<p><b>A</b>. Doppler ultrasound examinations were performed on tissue engineered vascular grafts from 2 weeks to 12 months after implantation. Doppler signals proximal to the graft, distal, and within the graft showed propagation of systemic arterial impulse through the graft. <b>B.</b><i>In vivo</i> microCTs were performed at 4, 8, and 12 months. Using image analysis software, luminal volume measurements were recorded and then standardized to a 3mm segment. <b>C. & D.</b> When compared to native Aorta in mice having undergone sham operation, there was no significant difference in luminal diameter between both groups and in ratio of TEVG to native aorta at any of the time points.</p

Expression of vascular cell markers in TEVG was similar to that of native aorta.

<p>A. Immuno-labeling of vascular cell markers on cross-sections of TEVG and native aorta. Left panel: von Willebrand factor (vWF, green), an endothelial cell marker and CD68 (red), a macrophage marker. Middle panel: CD31 (red), an endothelial cell marker; alpha-smooth muscle actin (α-SMA, green), a marker of smooth muscle cell and myofibroblasts. Right panel: CD31 (red) and collagen type I (Col-1, green). DAPI is for nucleus staining (blue). <b>B.</b> Immune-labeling of intracellular adhesion molecule (ICAM) as a marker of endothelial cells.</p

Extracellular matrix deposition was evident in TEVG over the course of the 12-month experiment.

<p><b>A.</b> Histologic analysis of graft tissue testing for elastin (EVG: Elastica van Giesen), collagen, elastic and cellular architecture (Movat’s and Masson trichrome) (n = 5 in each group). There is minimal elastin within the graft as compared to that that seen in native aorta. There is presence of endothelial and adventitial cells of the grafts with neo-collagen containing extracellular matrix. <b>B.</b> Expression of extracellular matrix components (n = 5–10 in each group). SMC, a marker of smooth muscle cells. Data were normalized using hypoxanthine-guanine phosphoribosyltransferase (HPRT).</p

Macrophage infiltration and matrix metalloproteinase activity peaked at 4 months after implantation of TEVG.

<p><b>A.</b> Immunohistochemical analysis of macrophage and matrix metalloproteinase-2 (MMP-2) levels. Macrophage infiltration in TEVG was assessed by F4/80 staining, while MMP-2 staining was used for an indicator of TEVG remodeling. (n = 5 in each group). <b>B.</b> Endothelial layer staining delineates presence of an endothelium by von Willebrand factor (vWF, green) in implanted TEVG at 12 months after implantation. There is macrophage infiltration of the periphery of the graft (CD68, red) with nuclear (DAPI staining, blue). <b>C.</b> Real-time PCR analysis. Data indicate that macrophage infiltration and MMP-2 and -9 expression were most robust at 4 months after implantation (n = 5–10 in each group).</p

Assessment of TEVG morphometry using microCT angiography demonstrated absence of aneurysmal dilatation or stenosis 12 months after Implantation.

<p><b>A.</b> High resolution post-mortem microCT angiography at 12 months post-implantation. The results indicated smooth endoluminal surface and absence of aneurysmal dilatation or stenosis. Yellow bar indicates approximate location of tissue engineered vascular graft. TEVG resemble native aorta on microCT throughout the 12 month-experiment. (n = 5 in each group). <b>B.</b> Luminal volume. MicroCT image processing software was used for the calculation. Because of the difficulty in identifying proximal and distal anastomoses, graft luminal volumes were standardized to a 3mm segment. No significant changes were noted over the course of the experiment.</p

TEVG implantation was successful as indicated by a similar survival rate at 12-month post-operation in TEVG group to sham group.

<p>A. Structure of TEVG. Implanted TEVG was composed of biodegradable electrospun polylactic acid (PLA) nanofibers with a length of approximately 3mm and inner luminal diameter 500–600 μm. Scanning electron microscopy demonstrates macro- and micro-arrangement of graft. <b>B.</b> TEVG after surgical implantation (IVC: inferior vena cava; Ao: aorta). <b>C.</b> Survival rate at 24 hours after surgery. 25 TEVGs were implanted in C17SCID/bg mice. 12 syngeneic mice underwent sham operations. >90% of mice implanted with TEVG survived 24 hours after TEVG implantation. Peri-operative mortality was due to bleeding or thrombosis. <b>D.</b> Kaplan-Meier survival curve during the 12 months of experiment. Similar survival rate was seen between two groups over the course of 12 month-experiment.</p