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Figure 2. Biodistribution and microglial uptake of Pn-EVs@P110. (A) Representative in vivo IVIS images of mice following intravenous administration of PBS, free DiR, or DiR-labeled Pn-EVs@P110 at 1, 4, and 12 h; (B) Quantification of brain radiant efficiency at the indicated time points; (C) Representative ex vivo IVIS images of major organs (brain, heart, liver, spleen, lung, kidney); (D) Quantification of radiant efficiency in each organ; (E) Representative confocal images of perihematomal brain sections showing PKH67-labeled Pn-EVs@P110 (green) colocalized with Iba-1+ microglia (red) and DAPI (blue). Right panels show enlarged views; arrows indicate colocalization; (F) Representative confocal images showing time-dependent uptake of labeled Pn-EVs@P110 by BV2 microglia under control or LPS stimulation (0.5, 3, and 6 h); (G) Quantification of relative intracellular Dil fluorescence intensity at the indicated time points. Data are presented as mean ± SD. For (A-E), n = 3 mice/group; for (F and G), data were obtained from three independent biological experiments (n = 3). Statistical comparisons are indicated by the brackets; ^*P < 0.05, ^***P < 0.001. Pn-EVs: Panax notoginseng-derived extracellular vesicle-like nanovesicles; IVIS: in vivo imaging system; PBS: phosphate-buffered saline; DiR: 1,1’-dioctadecyl-3,3,3’,3’-tetramethylindotricarbocyanine iodide; DAPI: 4’,6-diamidino-2-phenylindole; Iba-1: ionized calcium-binding adapter molecule 1; LPS: lipopolysaccharide; Dil: 1,1’-dioctadecyl-3,3,3’,3’-tetramethylindocarbocyanine perchlorate; SD: standard deviation; PKH67: PKH67 Green Fluorescent Cell Linker Dye; ns: not significant.