Experimental investigation on the factors affecting VWF damage based on an in vitro blood-shearing platform

With the increasing number of people suffering from heart failure,ventricular assist devices have gradually become an effective way to treat end-stage heart failure.However,the blood damage caused by ventricular assist devices has not been effectively solved,which is an obstacle to its clinical promotion.Most research focused on erythrocyte damage under shear stress,while few researches were conducted on the interaction between blood under shear stress and the induction of von Willebrand factor(VWF)damage.This research used a vortex oscillator blood-shearing platform to conduct in vitro experiments and used immunoblotting to quantify VWF damage in sheared samples to study the laws of shear-induced VWF damage under different shear stress,different exposure times,different blood components,and hemolysis conditions.It was found that VWF damage increased with exposure time and shear stress.At the same time,under lower shear stress,other blood components had little effect on VWF damage,while in a higher shear stress,other blood components would accelerate VWF damage.Hemolysis will also affect VWF damage,and the higher the degree of hemolysis,the higher the rate of VWF degradation in the plasma.The results of this research provide a reference for VWF damage evaluation standards and follow-up research and also guide for improving the design of ventricular assist devices to reduce VWF damage.