Patient-specific modeling of individual sickle cell behavior under transient hypoxia
(a) Morphological transition of RBCs from the biconcave to different sickle shapes under transient hypoxic conditions. Labels A–D represent the position of the anchor points, which are represented by εNv (ε = 0.016) vertices. (b) Schematic of microfluidic device with O2 control for kinetics of cell morphological sickling and unsickling as well as single cell biorheology test. The microfluidic channel contains periodic obstacles forming 15-μm-long, 4-μm-wide and 5-μm-high microgates, mimicking the size of the smallest capillaries in human body. (c) Cell sickling and unsickling process in response to change in O2 concentration as a function of time (from companion experiments). Simulations of five sequential snapshots of the RBC shape evolution at O2% = 19.8%, 8.1%, 2.5%, 12.7%, and 19.9%, from left to right. These conditions correspond to the red circles indicated in the O2 versus time plot. See S1 Video for dynamic shape changes occurring in response to alterations in oxygen concentration.