| 초록 |
We hypothesized that pulsatile shear stress induces the feature of VSMCs in in vitro engineered tissues to be similar to that of VSMCs and endothelial cells(ECs) in native vascular tissues. To test the hypothesis, aortic SMCs were seeded onto elastic, three-dimensional scaffolds and ECs were injected into the lumen cultured in vitro under a pulsatile shear stress condition. After 1 week static culture, the grafts were grown in vitro in pulsatile radial strain bioreactor for 1, 3, 5, and 8weeks. Pulsatile shear stress was applied to the vessels at 120 beats per minute (bpm) and 8% radial distention. Controls were grown in static culture conditions. A significant SMCs alignment in a direction parallel to the pulsatile radial direction was found in the VSM tissues exposed to pulsatile radial strain. The cellular alignment and alignment direction are consistent with those of native vascular SM tissues, in which VSMCs in vivo align in the radial direction (parallel to pulsatile radial direction). In control tissues (SM tissues engineered with static culture), cells randomly aligned. The expression of VSM actin and VSM myosin heavy chain, phenotypic markers of SMCs in a contractile state, was upregulated in the stretched tissues by 2.5 and 2.0 fold, respectively, compared to SMCs in the control tissues. Pulsatile radial strain increased protein amount, SM Actin, SM MHC, enhanced the alignments of SMCs and ECs, yielded more native-like SMC and clear EC layer.εε |
