Journal: Bioactive Materials

Article Title: Inhalable PD-L1-engineered hybrid cellular vesicles suppress excessive neutrophil activation and restore mitochondrial homeostasis to alleviate ischemia–reperfusion lung injury and pneumonia

doi: 10.1016/j.bioactmat.2026.03.024

Figure Lengend Snippet: Nebulized Res-PD-L1@nmEVs Target and Attenuate Lung Ischemia-Reperfusion Injury (A) Experimental timeline: rats undergoing lung IRI received nebulized treatments (Res, nEVs, PD-L1@mEVs, PD-L1@nmEVs, or Res-PD-L1@nmEVs) before ischemia and after reperfusion, with sample collection 2 h post-reperfusion. (B) Ex vivo organ fluorescence imaging 24 h after intravenous or bronchial nebulization of DiR-labeled Res-PD-L1@nmEVs. (C) In vivo lung distribution of nebulized DiL-labeled PD-L1@mEVs and PD-L1@nmEVs evaluated using a small animal dynamic imaging system. Blue: CD31 (vascular marker), Red: DiL. (D-E) Quantitative fluorescence intensity in ex vivo organs (heart, liver, spleen, lungs, kidneys) at 0–24 h after bronchial nebulization of DiR-labeled Res-PD-L1@nmEVs in Sham and IRI groups. (F-G) Representative H&E-stained lung sections (F) and corresponding lung injury scores (G). (H) Lung wet/dry weight ratio. (I-K) Levels of inflammatory cytokines in lung tissue. (L-N) Pulmonary oxidative stress markers: T-SOD2 activity (L), GSH/GSSG ratio (M), and MDA content (N). (O) Representative fluorescence images of ROS in lung tissue. Scale bar: 50 μm. (P-R) Immunofluorescence staining and co-localization of tight junction proteins Occludin-1 (green) and ZO-1 (red) in lung tissues (DAPI: blue). Scale bar: 50 μm. Quantitative analysis of ZO-1 (Q) and Occludin-1 (R) fluorescence intensity. ∗ vs. Sham; # vs. IRI; & vs. IRI + PD-L1@nmEVs, p < 0.05.

Article Snippet: Pulmonary function was assessed using a small animal pulmonary function system (Data Sciences International, Buxco system, DSI, USA).

Techniques: Ex Vivo, Fluorescence, Imaging, Labeling, In Vivo, Marker, Staining, Activity Assay, Immunofluorescence