Fig. 3

SEM images of GaP NWs embedded in lung tissue day 1 (a, b), day 28 (c, d) and 3 months (e, f) post-exposure. The right panel images show the NWs indicated by arrows in the left panels at higher magnification. Alv: alveoli, BV: blood vessel. Scale bars 4 μm (a), 1 μm (b), 10 μm (c), 1 μm (d), 2 μm (e) and 0.5 μm (f). (g) Chemical identification of gallium (Ga) and phosphorus (P) in NWs in lung tissue 1 day after exposure. SEM and EDS, scale bars 1 μm. (h) NW dissolution in vivo in lung tissue and in vitro in simulated phagolysosomal fluid (PSF) and simulated lung lining fluid (Gamble’s, GB). N = 3, at least 30 NWs were measured per time point