Formulation and evaluation of a particulate oral breast cancer vaccine

Breast cancer being the most fatal form of cancer for female population, justifies exploration of immunotherapy as an alternative treatment. Here, we have formulated and evaluated an oral microparticulate breast cancer vaccine to provide a new line of therapy. The whole cell lysate of 4T07 murine breast cancer cells was incorporated in an aqueous polymer matrix and spray dried to formulate an enteric protected vaccine microparticle. These particles were characterized in vitro and then administered orally to female Balb/c mice in successive boosters. Serum antibody titers during the study were analyzed using enzyme-linked immunosorbent assay. Postvaccination animals were challenged with live 4T07 cells, and tumor growth was monitored. Flow cytometry studies were performed to analyze the role of T cells. Results show that the vaccine microparticles were 1-4 µm in volume diameter and neutral in charge. The particles were protected enterically and had sustained-release profile. Serum antibody titers of vaccinated animals increased significantly after boosters compared with controls (p < 0.05). Tumor challenge studies revealed that vaccinated animals developed significantly smaller tumors (p < 0.05). Significantly higher numbers of CD4(+) cells occurred in vaccinated animals (p < 0.05). Thus, we conclude that the particulate oral breast cancer vaccine was effective in providing protective immune response in the murine model.