Fig. 4: Particles reduce lipopolysaccharide (LPS)-induced neutrophil-platelet aggregate adhesion in mouse mesentery.

a Timeline, dosing scheme, and experimental schematic of intravital microscopy of inflamed mouse mesentery. Mice received an intraperitoneal (IP) injection of LPS and a retroorbital (RO) injection of labeling antibodies at t = 0, and for particle groups, a RO injection of particles at t = 0 (‘prevention’) or t = 2 h (‘intervention’). Mice were imaged at t = 3 h after LPS injection. b Representative still image of merged brightfield microscopy, fluorescent Brilliant Violet 421 Ly6G+ neutrophils (blue), FITC polystyrene particles (green), anti-GP1b DyLight 649 platelets (red) channels within mouse mesenteric blood vessel for an LPS-only (non-particle treated; left) and untargeted (UT) Prevention (right) mouse. Neutrophil, platelet, and particle adhesion were quantified only within blood vessels, edges of which are denoted with dashed arrows. Small white arrows highlight several platelet-neutrophil aggregates, scale bar 100 µm. Quantified results of (c) platelet adhesion scaled by the surface area of the blood vessel, (d) platelet adhesion fold change of UT particle-treated mice relative to LPS-only mice, and (e) neutrophil (PMN) adhesion in mouse mesentery 3 h after IP injection of LPS, scaled by the surface area of the blood vessel. Quantified (f) platelet adhesion, or (g) neutrophil adhesion fold change of T particle-treated mice (intervention) relative to LPS-only mice. Experimental groups consist of N = 5 mice per group with 2–4 independent vessels imaged per mouse. Statistical analyses were performed using a one-way ANOVA with Tukey’s multiple comparisons (c–e) or a two-tailed unpaired Student’s t test (f, g). (*) indicates p < 0.05 and (**) indicates p < 0.01 in comparison to LPS-only controls (c–e) or UT intervention (f, g). Calculated p-values are listed when relevant. Lack of symbols indicates no statistical significance. Circles represent individual data points, bar graph represents the average of individual data points, and error bars represent standard error. Source data and specific p-values are provided as a Source Data file.