Figure 1.
Double-sided shear stress bioreactor setup.
Setup schematic (A) and tissue isolation and mounting (B) (R: radial tissue direction; C: circumferential tissue direction).
Figure 2.
Native TAV and BAV WSS environments.
Side-specific WSS waveforms predicted by fluid-structure interaction simulations in the base region of TAV (A) and type-I BAV leaflets (B) (F: fibrosa; V: ventricularis).
Figure 3.
Shear stress bioreactor mechanical validation.
Comparison between the programmed and measured cone angular velocities for the production of the TAV and NC-BAV ventricularis and fibrosa WSS (rms error expressed as a percentage of the maximum shear stress range experienced by the leaflet over one cardiac cycle).
Figure 4.
Effects of TAV and BAV WSS on tissue structure and cell viability.
H&E stain (A), mean tissue thickness measurements (B), TUNEL assay (C) and quantitative TUNEL results (D) in porcine aortic valve leaflets subjected to TAV and BAV WSS (F: fibrosa; V: ventricularis, green: apoptotic cells, blue: cell nuclei).
Figure 5.
Effects of TAV and BAV WSS on endothelial activation.
ICAM-1 and VCAM-1 immunostaining in porcine aortic valve leaflets subjected to TAV and BAV WSS (F: fibrosa; V: ventricularis; green: positively stained cells; blue: cell nuclei).
Figure 6.
Effects of TAV and BAV WSS on paracrine signaling.
BMP-4 and TGF-β1 immunostaining (A), immunoblotting (B) and densitometric results (C) in porcine aortic valve leaflets subjected to TAV and BAV WSS (F: fibrosa; green: positively stained cells; blue: cell nuclei; *: p<0.05 vs. fresh control; #: p<0.05 vs. TAV WSS; +: p<0.05 vs. NC-BAV WSS).
Figure 7.
Effects of TAV and BAV WSS on α-SMA and Runx2 expressions.
α-SMA and Runx2 immunoblotting (A) and densitometric results (B) in porcine aortic valve leaflets subjected to TAV and BAV WSS.
Figure 8.
Effects of TAV and BAV WSS on valvular remodeling.
MMP-2, MMP-9, TIMP-2, cathepsin L and cathepsin S immunostaining (A), semi-quantitative results (B) and TIMP-2/MMP-2 ratio (C) in porcine aortic valve leaflets subjected to TAV and BAV WSS (F: fibrosa; green: positively stained cells; blue: cell nuclei; *: p<0.05 vs. fresh control; #: p<0.05 vs. TAV WSS).
Figure 9.
Effects of TAV and BAV WSS on gelatinase activity.
MMP-2 and MMP-9 gelatin zymography (A) and active MMP-2 and MMP-9 semi-quantitative results (B) in porcine aortic valve leaflets subjected to TAV and BAV WSS (*: p<0.05 vs. fresh control; #: p<0.05 vs. TAV WSS; +: p<0.05 vs. NC-BAV WSS).
Figure 10.
Effects of TAV and BAV WSS on valvular osteogenesis.
Osteocalcin immunostaining (A), immunoblotting (B) and densitometric results (C) in porcine aortic valve leaflets subjected to TAV and BAV WSS (F: fibrosa; green: positively stained cells; blue: cell nuclei; *: p<0.05 vs. fresh control; #: p<0.05 vs. TAV WSS; +: p<0.05 vs. NC-BAV WSS).