Figure 3. Neuroblastoma-specific phage clones target an orthotopically implanted mouse model of human NB and spare targeting healthy tissues in in vivo experiments.

The capability of the NB-targeting phage clones to home to tumors was evaluated after their i.v. administration into mice bearing human GI-LI-N NB-derived orthotopic xenografts (3 animals/group). Insertless Fd-Tet phage was injected as a negative control. After 10 min and 24 h, mice were perfused with complete medium and euthanized. Tumor tissues were explanted, Bouin-fixed, paraffin-embedded and co-stained with anti-fd bacteriophage (green) and anti-SMA-Cy3 (red) antibodies (A). B. Experiments were performed as described in A. Healthy ipsilateral and controlateral kidneys, liver and spleen were explanted, Bouin-fixed, paraffin-embedded and stained with anti-fd bacteriophage antibody. Staining were quantified on 5 confocal images/experimental point by Image J software and presented by histograms. Symbols used to report the statistical analysis: * = peptide-displaying versus insertless phage; § = 24 h versus 10 min phage circulation. *, p<0.05; **^{, §§}, p<0.01; ***^{, §§§}, p<0.001.