Fig. 1. Ex vivo uptake of particles of different ARs by primary human neutrophils.

(A) SEM image of the polystyrene particles of different sizes and ARs fabricated via the heat stretching technique in a PVA film. Scale bars, 1 μm. (B to D) The percentage of primary human neutrophils in whole blood that uptake fluorescent polystyrene particles with equivalent spherical diameters (ESDs) of (B) 2 μm, (C) 1 μm, and (D) 500 nm. The particle concentration in blood was set at 10⁷ particles/ml for (B) and (C) and at 10⁸ particles/ml for (D). (E) Effect of shape on the uptake of poly(lactic-co-glycolic acid) (PLGA) microparticles by primary human neutrophils. The concentration of the particles in blood was set at 5 × 10⁶ particles/ml. One-way analysis of variance (ANOVA) with Tukey’s posttest and confidence interval of 95% were used to analyze (B) to (D). Each condition was replicated for at least three individual donors. Unpaired t test was used to analyze (E) (ns, P > 0.05; *P < 0.05; **P < 0.01; ***P < 0.001).