| Our project is a novel multistep radioimmunotherapeutic approach to be used as an adjuvant treatment for ovarian cancer. The CA-125 antigen is located on the surface of ovarian cancer cells. First, anti-CA125 monoclonal antibodies (Mabs) B43.13 and B27.1 were purified and labeled with a long-armed biotin. Secondly, the free biotin concentration was less than 10nM as determined by a sensitive ELISA and may not significantly compromise the strategy of biotinylated liposome targeting. The biotin transport mechanism was studied to understand the inhibition of transporting and the potential non-specific binding of biotinylated liposomes. Finally, biotinylated liposomes were prepared and a preliminary in vitro study was performed to demonstrate the targeting of liposomes to ovarian cancer cells using confocal laser scanning microscopy (CLSM). The results indicated that biotinylated liposomes specifically bound to NIH OVCAR-3 human ovarian cancer cells via biotinylated monoclonal antibodies and a streptavidin-biotin system. |
