Development of an In Vivo Assay for Antibody-Conjugated Gold Nanoparticles Targeted to Human Pancreatic Tumor Xenografts Using an Ex Ovo Avian Embryo Culture System

Pancreatic cancer therapies remain limited in scope and patient prognoses remain poor. To effectively improve pancreatic cancer outcomes, a highly targeted therapeutic is necessary. A bioconjugated gold nanoparticle (AuNP) provides such a therapeutic platform. Effective targeting of the nanoparticle is possible through the linkage of antibodies to target key antigens highly expressed on the surface of cancerous tissue. Previous work using RT-PCR and Western blotting has established the over-expression of the membrane glycoprotein A33 (gpA33) in the CAPAN-2 pancreatic cancer cell line and the absence of gpA33 in the BxPC-3 pancreatic cancer cell line. This differential protein expression allows for an experimental paradigm in which uptake of AuNP conjugated with anti-gpA33 antibodies can be quantified and compared in vivo between CAPAN-2 and BxPC-3 xenografts. Avian embryos are used as the model animal system and cultured ex ovo. BxPC-3 and CAPAN-2 cell lines were cultured and injected into the chorioallantoic membrane (CAM) of day 8 embryos to induce formation of human tumor xenografts. Antibody-conjugated AuNP were delivered intravenously into the CAM vasculature. Xenografts were allowed to develop for seven days in vivo and subsequently excised, paraffin embedded and analyzed histologically and immunohistochemically to confirm expression patterns of gpA33 in sections of CAPAN-2 and BxPC-3 xenografts. Dot blot and Western Blot analyses demonstrated the presence of targeting antibodies within CAPAN-2 tissue and the absence of targeting antibodies in BxPC-3 tissue. This thesis project validates the in vivo targeting capability of an antibody-conjugated AuNP platform and lays the foundation for its use in the treatment of pancreatic adenocarcinoma.