Biophysical and biomolecular interactions of malaria-infected erythrocytes in engineered human capillaries

Microcirculatory obstruction is a hallmark of severe malaria, but mechanisms of parasite sequestration are only partially understood. Here, we developed a robust three-dimensional microvessel model that mimics the arteriole-capillary-venule (ACV) transition consisting of a narrow 5- to 10-μm-diameter capillary region flanked by arteriole- or venule-sized vessels. Using this platform, we investigated red blood cell (RBC) transit at the single cell and at physiological hematocrits. We showed normal RBCs deformed via in vivo–like stretching and tumbling with negligible interactions with the vessel wall. By comparison, Plasmodium falciparum–infected RBCs exhibited virtually no deformation and rapidly accumulated in the capillary-sized region. Comparison of wild-type parasites to those lacking either cytoadhesion ligands or membrane-stiffening knobs showed highly distinctive spatial and temporal kinetics of accumulation, linked to velocity transition in ACVs. Our findings shed light on mechanisms of microcirculatory obstruction in malaria and establish a new platform to study hematologic and microvascular diseases.