Fig 1: Inflammation-directed targeted delivery in vitro. (A) Representative confocal images of the uptake of M1-EXOs and iM1-EXOs-PAN by GB cells. Scale bar, 25 μm. (B) Quantification of the PKH67‐positive cell ratio based on the confocal microscopy images. (C) Schematic illustration of the in vitro BBB model using a trans-well system to evaluate the penetration capability of iM1-EXOs-PAN across the endothelial monolayer. The transwell co-culture system containing HUVEC cells (simulating the vascular endothelial cells of BBB) in the upper chamber and GB cells in the bottom chamber. And, iM1-EXOs-PAN was added to the upper chamber, and FBS free medium with or without fMLP (100 μM, MCE, HY-P0224) was added to the lower chamber. (D) Representative images of HUVECs and LN229 cells up-taking the nanoformulation treated with chemotactic peptide (+fMLP, 100 μM) or none (-fMLP) at 12 h. Scale bar, 20 μm. (E) The percentage of PKH67 positive cells treated with chemotactic peptide (+fMLP, 100 μM) or none (-fMLP) at 4, 8, and 12 h. Statistical significance was calculated using two-way ANOVA. n. s = not significant, and ∗∗∗P < 0.001.