Fig. 4

774A.1 macrophages were incubated for 2 h at 37 °C with medium only or with medium containing 2.0 μM paramagnetic and Rhodamine B-labeled discoidal HDL (dHDL) or spherical HDL mimicking NPs synthesized using a 1:1 mixture of oxidized synthetic apoA-I peptides H4 and H6. a Fluorescence intensities of cell lysates were measured and normalized to total cell protein content. b Loosely packed cell pellets were generated and T1 values were measured using T1-weighted MR imaging of cell pellets incubated with medium alone, dHDL mimicking NPs or sHDL mimicking NPs. c Normalized enhancement ratio (NER) values for cell pellets are calculated from corresponding T1-weighted images and are relative to cells incubated with medium only. d Contrast-to-noise ratio (CNR) values for cell pellets are calculated from the corresponding T1-weighted images and are relative to cells incubated with medium only. e Differential interference contrast (DIC) image of a single representative J774A.1 macrophage incubated with sHDL (similar images were obtained for dHDL). 4′,6-diamino-2-phenylindole (DAPI) dye (blue), Dylight 488-labeled peptide H4 (green), Rhodamine B-labeled lipid (red) and merged image. f Representative axial T1-weighted images of ApoE^−/− mice, collected before (Pre) and 4 h, 24 h, 48 h and 72 h after administered with the equivalent of 0.05 mmol Gd kg⁻¹ of paramagnetic and Rhodamine B-labeled dHDL or sHDL mimicking NPs. The insets in each scan show the original images, which were cropped and enlarged to highlight the aorta. g NER values (mean ± SD) of mouse aorta wall following contrast administration were calculated for each of the time points (n = 5 slices) for the representative mouse using the corresponding T1-weighted images and are relative to muscle. h CNR values (mean ± SD) of mouse aorta wall following contrast administration were calculated for each of the time points (n = 5 slices) using the corresponding T1-weighted images and are relative to muscle.