Phagocytosis of PODS protein crystals into professional phagocytes. PODS Empty, PODS M-CSF, and GM-CSF represent PODS containing no cargo protein, M-CSF, and GM-CSF, respectively. GM-CSF: granulocyte-macrophage colony-stimulating factor; M-CSF: macrophage colony-stimulating factor. (a) Brightfield images of PODS M-CSF and GM-CSF loaded bone marrow-derived mouse macrophages at a magnification of 40x with a scale bar of 100 μm. The dashed square marks the area of the zoom shown in the right image of each panel. (b) Schematic overview of the THP-1 differentiation (M0), polarization (M1, M2), and PODS phagocytosis workflow. (c) THP-1 cells were differentiated first into M0 macrophages and then further polarized into either M1 or M2 macrophages according to the workflow depicted in (b). Cells of the various differentiated types were cultured with PODS Empty at a concentration of 10 PODS per cell for 24 h and subsequently imaged at a magnification of 40x. The scale bar is 100 μm.