Identification of nanoATV in cells after intramuscular administration.

Balb/c mice injected intramuscularly with 100 mg/kg CF633-nanoATV were sacrificed on days 1 and 7 after injection. Cryosections were prepared for H&E staining and for confocal microscopy. (A) Flow cytometric analysis of spleen demonstrates significant uptake of nanoATV in macrophages (CD45+CD3-CD11b+F4/80+) compared to lymphocytes (CD45+CD3+) and neutrophils/granulocytes (CD45+CD3-CD11b+F4/80-) at days 1 and 7. Data are represented as mean per mouse ± SEM and considered significant at P<0.05 (Student’s t-test). (B) Cryosections of muscle at the site of injection stained with H&E; 40X. (C) The muscle cryosection was stained with DAPI for nuclei (blue). The red arrowheads show the accumulation of nanoATV at the site of injection, 63X. (D) Macrophages were immunostained with CD68 antibody and Alexa Fluor 488 secondary antibody. Colocalization of nanoATV (pink) and CD68+ cells (green) at the site of injection is indicated with red arrowheads. Nuclei were stained with DAPI (blue), 63X. (scale bars = 10 μm)