Development and Characterization of Targeted Iron Oxide Nanoparticles for Pancreatic Tumor Therapy

The challenge of specificity remains a great obstacle in modern cancer therapeutics. Pancreatic cancer patients, with a survival rate of less than 5%, are particularly reliant on the specificity of drug therapies due to late diagnosis and non-resectable tumors. This study investigates the targeting of an iron oxide nanovehicle with the novel monoclonal antibody, CHO31.1, to the surface antigen on pancreatic tumor cells, GPA33. This nanovehicle is part of a larger project focused on the development of iron oxide nanoparticles loaded with atoms of 10B for selective irradiation of tumors via boron neutron capture therapy (BNCT). Success of this therapy depends on effective concentrations of SPIO nanoparticles within tumor cells for tracking within MRI. Conjugation of antibodies to the surface of Ferrotec EMG304 ® particles was investigated through 3 different routes: 1) hydrazone bond formation 2) hinge thiol attachment and 3) carbodiimide coupling. Coupling methods were characterized with UV-visible spectroscopy, chemiluminescent dot blot, and SDS-page electrophoresis. Efficient binding of particles to the antigen target was investigated through a pull down assay with lysates of CAPAN-2 pancreatic cells expressing the target antigen, GPA33. Surface protein was quantified with a BCA assay and zeta potential measurements of the targeted particles were obtained. MRI in vitro assays were performed with the targeted particles. Particles were successfully and reproducibly coupled to antibodies via carbodiimide coupling. Total protein content on the surface of particles showed that uncoupled particles persisted in solution. Efficient binding of GPA33 target was shown in the pull down assay with CAPAN-2 lysates. In-vitro assays of particles did not show significant uptake by cancer cells. Future work to investigate the effects of surface charge and aggregation of targeted nanoparticles should be performed.