Single-cell real-time imaging of flow-induced hemolysis using high-speed microfluidic technology

Understanding the mechanism of flow-induced blood cell damage, such as hemolysis and platelet activation, plays an important role for arterial diseases and artificial organs. This study for the first time demonstrates the visualization of flow-induced hemolysis in a single-cell real-time manner using high-speed microfluidic technology. Impinging microjets with a velocity of 1.5 m/s order at a nozzle exit were made in the Y- and T-shaped microchannel. The curved (r=10μm) and flat collision surface were compared. Porcine fresh erythrocytes were suspended in PBS at Ht=0.5%. Results showed that membrane failure was only observed in the Y-junction. These erythrocytes were initially elongated at the far region, and then longitudinally compressed in the near wall region due to the sharp adverse pressure gradient, whereas those in the T-junction released the membrane tension as the pressure difference per erythrocyte diminished. In the simulation of energy balance, it was found that the dominant force for the longitudinal compression was the pressure difference per erythrocyte. Such erythrocytes showed the sudden drop of elastic modulus, suggesting that the elongated spectrin network of erythrocyte was fragile for the compressive force and immediately broken by the impact force.