Institute of Biomechanics,School of Bioscience and Bioengineering,South China University of Technology
The National Natural Science Foundation of China (General Program, Key Program, Major Research Plan)
Objective To investigate effects of wall shear stress on rolling adhesion of neutrophils on immobilized platelets under flows. Methods Experiments were performed with the parallel plate flow chamber technology. Platelets was adhered to the functionalized flow chamber bottom which had been coated with vWF-A1 first, and then was washed with PBS under wall shear stress of 10 dyn/cm2 for different time (0 min, 2.5 min, 7.5 min). A high-speed camera was used to observe and record the rolling adhesion events of neutrophils on immobilized platelets under wall shear stress of 0.5 dyn/cm2, and the adhesion parameters such as the number of adhesion events, the tether lifetime of cells, and rolling velocity. Results Neutrophils can specifically bind to the immobilized platelets on vWF-A1-coated bottom of the flow chamber. Preloading of wall shear stress on the immobilized platelets has no effects on the tether lifetime of neutrophils on the platelets, but up-regulates the adhesive ratio of neutrophils on the platelets and makes the rolling of neutrophils on the platelets slow down. Conclusions Preloading of wall shear stress on the immobilized platelets will significantly make the circulating neutrophils to be captured easily and promote the rolling adhesion of neutrophils on platelets.