Figure 4

Histological findings of lungs representing peribronchial and perivascular tissues in the (a) control group, (b) S-SNP group, (c) M-SNP group and the (d) P-SNP group. M-SNP, mesoporous silica nanoparticle; P-SNP, PEGylated silica nanoparticle; S-SNP, soluble silica nanoparticle.