Effects of shear stress on cytoskeleton alignment, adhesion, migration and apoptosis of endothelial cells on micropatterned substrates

BACKGROUND: Micro-nano-sized modification of the material surface provides an effective way to enhance the endothelialization of cardiovascular implants. Shear stress plays an important role in the endothelialization of cardiovascular implants. OBJECTIVE: To review the effects of flow shear stress on endothelial cell cytoskeleton alignment, migration, adhesion and apoptosis on the micropatterned substrates. METHODS: The author performed a retrieval of PubMed and CNKI databases from 2002 to 2017 to search literatures about the effects of shear stress on endothelial cells on the micropatterned substrates. The keywords were “micrometer topology, micropattern, flow shear stress, endothelial cells” in English and Chinese, respectively. RESULTS AND CONCLUSION: The shear stress parallel to the long axis of the micropattern which is applied to the endothelial cells on micropatterned substrates promotes endothelial cell microfilaments alignment along the long axis direction of micropattern, strengthens endothelial cell migration along the flow direction, increases the level of FAK phosphorylation, enhances endothelial cell adhesion, and improves endothelial cell activity. However, there are some controversies on the effects of parallel shear stress on the microtubule arrangement of endothelial cells on micropatterned substrates. Some studies have reported that parallel shear stress promotes endothelial cell microtubules alignment along the long axis of micropatterns. But others have found that parallel shear stress has no effect on endothelial cell microtubule arrangement. There are different conclusions about the effects of shear stress perpendicular to the long axis of the micropattern on endothelial cells on the micropatterned substrates. Some literatures have found vertical shear stress destroys the structure of endothelial cell microfilaments and microtubules, weakens the degree of microfilaments and microtubules arranged along the long axis of micropatterns, and attenuates endothelial cell adhesion and cell activity. But some have found vertical shear stress does not destroy the structure and alignment of endothelial cell microfilaments and microtubules, and still can promote endothelial cell migration along the flow direction. The magnitude of shear force affects endothelial cell migration, and the number of endothelial cells on the micropatterned substrates migrating along the flow direction increases with the increasing intensity of shear stress.