Fig. 4

Effect of binding on DG-predicted dose metrics. Effect of particle/agglomerate binding to cells (well bottom) on DG model dose metrics for SiO2 (a, b), Fe₂O₃ (c, d), and TiO2 (e, f). For all simulations C ₀ = 0.1 mg ml⁻¹, column height = 3 mm, and d _H = volume-averaged mean (Table 1). Langmuir isotherm adsorption was used to model binding of agglomerates to the well bottom at various values of the dissociation constant K _D. a, c, e Exposure mass ENM concentration, C _bottom (mg cm⁻³ in bottom 10 μm, including ENM within both bound and free agglomerates). b, d, f Mass of ENM bound per well bottom area (mg cm⁻²)