Figure 8.

Determination of the effects of the production of anti-targeting ligand antibody on efficiency of intratumoral nanoparticle delivery. Mice bearing 4T1 mammary tumors received tail vein deliveries of 200 pmol of different IONPs once per week for three injections (A &B). A. T₂-weighted MRI was performed 24 hours after the last injection. Pink-lined areas were mammary tumors. Numbers in the figure were the mean MRI signal intensity of the entire tumor. B. Histological analysis of tumor tissue sections using Prussian blue staining. Tumors were collected 48 hours after the third injection. Paraffin tissue sections were used for Prussian blue staining. Blue: IONP positive cells; Red: nuclear fast red background staining. C. Balb/c or SCID mice bearing 4T1 mouse mammary tumors received tail vein injections of 300 pmol of NIR-830-ScFvEGFR-IONP or NIR-830-ScFvEGFR-PEG-IONP once every 5 days for three injections. 72 hours following the last injection, the mice were sacrificed. Tumors were excised for ex vivo organ optical imaging, which provided more accurate quantification of optical imaging signals that reflected the level of IONP accumulation. Yellow arrows: comparison of optical imaging of tumors in Balb/c or SCID mice treated with NIR-830-ScFvEGFR-PEG-IONP; Pink arrows, optical imaging of tumors of Balb/c or SCID mice that received NIR-830-ScFvEGFR-IONP. Mean signal intensity and standard derivations of each tumor are shown. The levels of anti ScFvEGFR-antibody in mouse serum samples shown are O.D. 450 nm at a mouse serum dilution of 1:5000. Prussian blue staining of frozen tumor sections revealed the accumulation of IONPs in tumor tissues.