Statin-treated RBC dynamics in a microfluidic porous-like network

The impact of therapeutic interventions on red blood cell (RBC) deformability and microscale transport is investigated, using statins as an exemplar. Human RBCs were treated in vitro with two commonly prescribed statins, atorvastatin and rosuvastatin, at clinically relevant concentrations. Changes in RBC deformability were quantified using a microfluidic-based ektacytometer and expressed in terms of the elongation index. Dilute suspensions of the statin-treated RBCs were then perfused through a microfluidic pillar array, at a constant flow rate and negligible inertia, and imaged. Particle Tracking Velocimetry (PTV) was applied to track RBCs, identify preferential paths and estimate their velocities, whereas image processing was used to estimate cell dynamics, perfusion metrics and distributions. The findings were compared against those of healthy, untreated cells. Statins enhanced RBC deformability in agreement with literature. The extent of enhancement was found to be statin-dependent. The softer statin-treated cells were found to flow in straight, less tortuous paths, spend more time inside the pillar array and exhibit lower velocities compared to healthy RBCs, attributed to their enhanced deformation and longer shape recovery time upon impact with the array posts. The in vitro microfluidic approach demonstrated here may serve as a monitoring tool to personalise and maximise the outcome of a therapeutic treatment.