Figure 5.

pMCNPs were systemically injected to athymic mice through the tail-vein and in vivo and ex vivo NIRF imaging demonstrated tumor accumulation and bio-distribution of pMCNPs.

Notes: At 24 h postinjection, we performed in vivo whole body and ex vivo NIRF imaging of major organs, including tumors, by IVIS. All images were normalized. In the whole body image, pMCNPs predominantly accumulated at the tumor site (A). The accumulation was also validated by ex vivo imaging of the organs and tumor. The nanoparticles specifically accumulated in even small solid tumors of 5 mm in diameter. The black dotted lines indicate the actual edge of the solid tumors. Without particle injection, we did not find high NIRF signals (B). pMCNP accumulation in the tumor clearly differed in liver, spleen, kidneys (*P<0.03), lung and heart (**P<0.0001). (C).

Abbreviations: CNPs, chitosan nanoparticles; IVIS, in vivo imaging system; NIRF, near infrared fluorescence; NPs, nanoparticles; H, high; L, low; pMCNPs, pCNPs loaded with 22 nm iron oxide NCs.