Monday  |  Salon 8  |  05:30 PM–05:50 PM

#15756, Mechanical Degradation of Red Blood Cells due to Cyclic Stretching and Cyclic Hypoxia

Red blood cells (RBCs) are known for their remarkable deformability, a key factor to fulfill its primary role in transport of respiratory gasses. Along with cell aging, their deformability decreases. Loss of deformability is seen faster in diseased RBCs, e.g., sickle cell disease, as compared to normal blood. As fatigue arising from cyclic loadings is known to be a key factor in the degradation of properties of engineered materials and natural biomaterials, we hypothesize that cyclic loadings lead to RBC mechanical degradation, as they are subjected to cyclic shear strains and cyclic partial pressure of oxygen (PaO2) oscillations when they travel through pulmonary and systemic circulatory systems and from large vasculature to small capillaries. To quantify the weakening of RBC deformability, we have developed a novel fatigue testing method, implemented with amplitude shift keying-modulated electrodeformation in a microfluidic platform. On-chip PaO2 control of RBCs is achieved through a gas permeable film in a double-layer Polydimethylsiloxane (PDMS) structure. This method is capable of subjecting individual RBCs to programmable cyclic stretching/relaxation and cyclic PaO2 variations for characterization of membrane deformability. The fatigue testing is demonstrated by RBCs in health and sickle cell disease subjected to cyclic stretching and cyclic hypoxia conditions. The results show that either type of cyclic loadings alone can lead to mechanical degradation in RBC membranes.

Sarah Du   Florida Atlantic University
Yuhao Qiang   Florida Atlantic University