Targeting gastrin receptors in an in vivo orthotopic-tumor model of pancreatic cancer. Human BxPC-3 pancreatic cancer cells were xenografted orthotopically into athymic nude mice. (A) One week following engraftment, ICG-loaded CPNPs were administered systemically via tail vein injection and near-infrared images were taken 24 hours post-injection. From left to right, mice receiving: (i) ICG-loaded, PEG-CPNPs, (ii) ICG-loaded, Gastrin- 10-PEG-CPNPs, or (iii) ICG-loaded, Pentagastrin-Avidin-CPNPs. (B) Excised, tumor-bearing, pancreases from each mouse, and excised brain (mouse ii). All images are representative of at least four independent experiment