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. Author manuscript; available in PMC: 2022 May 18.
Published in final edited form as: Nat Nanotechnol. 2021 Nov 18;17(1):86–97. doi: 10.1038/s41565-021-00997-y

Figure 1. Lysozyme-Dextran Nanogels and Crosslinked Albumin Nanoparticles Accumulate in Marginated Neutrophils in Inflamed Lungs.

Figure 1.

(a) Schematic of neutrophil margination and extravasation in inflamed lungs (created with BioRender.com). (b) Biodistributions of lysozyme-dextran nanogels (NGs) in naïve (n=4 animals) and IV-LPS-affected (n=8 animals) male C57BL/6 mice (red box: p<1×10−10, *: p=0.00008). (c) Biodistributions of PEG-NHS crosslinked human albumin nanoparticles (albumin NPs) in naïve (n=3 animals) and IV-LPS-injured (n=3 animals) mice (red box: p<1×10−10, *: p=0.004). (d-k) Flow cytometry characterization of single cell suspensions prepared from naïve and IV-LPS-affected mouse lungs. (d-e) Vertical axis indicates Ly6G staining for neutrophils and horizontal axis indicates signal from fluorescent NGs (d) or fluorescent albumin NPs (e). (f/h) NG/albumin NP fluorescent signal from neutrophils in IV-LPS-injured mouse lungs (red/pink), compared to naïve lungs (blue) (inset: Flow cytometry data verifying increased neutrophil concentration in IV-LPS-injured mouse lungs (red/pink). (g-h, j-k) Fraction of neutrophils positive for NGs (g) or albumin NPs (j) in naïve or IV-LPS-injured lungs and fraction of NG-positive (h) or albumin NP-positive (k) cells that are neutrophils. For (g-h), NGs/naïve: n=4 animals, NGs/LPS: n=4 animals. For (j-k), albumin NPs/naïve: n=3 animals, albumin NPs/LPS: n=3 animals. (g)*: p=2.6×10−7. (h)*: p=1.7×10−5. (j)*: p=0.0006. (k)*: p=0.007. (l-m) Fluorescence micrographs indicating association of NGs (red) with neutrophils (green, Ly6G stain) in the lungs of an IV-LPS-affected mouse (blue, tissue autofluorescence). Data are from histology for two naïve mice and two IV-LPS affected mice. (n) Single frame from real-time intravital imaging of NG (red) uptake in leukocytes (green) in the lungs of one IV-LPS-affected mouse (blue, Alexa Fluor 647-dextran). Statistical significance in (b) and (c) is derived from two-way ANOVA with Sidak’s multiple comparisons test. Statistical significance in (g), (h), (j), and (k) is derived from paired two-tailed t-tests. All error bars indicate mean ± SEM.