Flow shear stress promotes the endothelialization of small diameter tissue-engineered vessels / 中国组织工程研究

ABSTRACT

BACKGROUND: Magnitude and action ways of flow shear stress are important for the endothelialization of small diameter tissue-engineered vessels (TEV), and the TEV resistance ability to blood flow even decides the destiny of implantation. There are many studies on how to construct the TEV and improve anticoagulant ability of TEV after host cell implantation, but the effects of different flow shear stresses on the TEV endothelialization is rarely reported, which may be helpful for increasing the success rate of TEV implantation. OBJECTIVE: To compare the effects of flow shear stresses in single level or stepwise increased on the endothelialization of small diameter TEV and to optimize the TEV in the aspects of shear stress magnitude and loading method. METHODS: The number, morphology and adhesion ability of endothelial cells on the inner wall of TEV were observed through silver nitrate and F-actin staining. RESULTS AND CONCLUSION: Single-level shear stress at 2.5, 3.0 N/m2 for 2 hours removed almost all the endothelial cells seeded on the inner wall of TEV. In contrast, stepwise increased shear stress from 0.5 N/m2 to 3.0 N/m2 at an increase of 0.2 N/m2/2 hours maintained the integrity and oriented along the flow direction, and could induce stress fibers productionin endothelial cells. These results suggest that the stepwise increased flow shear stress can improve the endothelialization of TEV.