Fig. 3: Microbubble labeling is impacted by macrophage activity and polarization but does not impact macrophage polarization.

a Microscopy images showing different fates of MBs once phagocytosed—Retention, Digestion, Exocytosis. Scale bar 10 µm. “Created in BioRender. Kim (2025) https://BioRender.com/shd7dvr”. b Top left: iNOS stained untreated MΦs, bottom left: representative image of microbubbles uptake by untreated MΦs, top right: iNOS stained MΦs polarized to M1, bottom right: representative image of microbubbles uptake by M1 MΦs. The MФs were polarized with LPS (100 ng/ml) and IFN-γ (20 ng/ml). Scale bar 20 µm. Flow cytometry of cell viability (left) and expression of markers reflecting phenotype changes (right) following MB labeling in c RAW264.7 cell lines, d BMDM mice cells, e primary human macrophages, and f primary human DCs. (n = 5 wells for RAW264.7, n = 5 animals for BMDMs, n = 5 wells for human macrophages and DC). Data are presented as mean values ± SD. p values were determined by using two tailed unpaired t-test c left, d left, e left and f or a two-way ANOVA followed by Tukey’s multiple comparisons c right, d right, e right. n.s. not significant. g–i Optical density read by ELISA assay of IL4, IL6, IL 10, and TNF released in the 24 h following RAW264.7 macrophages, BMDMs and human macrophages labeling compared to non-labeled. (n = 3 wells for RAW264.7, n = 3 mice for BMDMs, n = 4 wells for human macrophages). Data are presented as mean values ± SD. p values were determined by using a two-tailed unpaired t-test with Holm-Šídák correction; n.s. not significant. Source data are provided as a Source Data file.