Targeting and anti-tumor efficacy of liposomal 5′-O-dipalmitoylphosphatidyl 2′-C-cyano-2′-deoxy-1-β-d-arabino-pentofuranosylcytosine in mice lung bearing B16BL6 melanoma

2′-C-cyano-2′-deoxy-1-β-d-arabino-pentofuranosylcytosine (CNDAC) is a potent anti-cancer agent, and we previously observed that liposomal formulation of 5′-O-dipalmitoylphosphatidyl derivative of CNDAC (DPP-CNDAC) is desirable for targeting. For targeting to pulmonary cancer, we investigated the in vivo behavior of liposomes containing DPP-CNDAC by a non-invasive method using positron emission tomography. Liposomes composed of DPP-CNDAC and cholesterol (DPP-CNDAC/CH liposomes) were markedly accumulated in mice lung bearing B16BL6 melanoma. In metastatic pulmonary cancer model, DPP-CNDAC/CH liposomes significantly reduced the lung colonization in a dose-dependent manner. The activity was significantly superior to conventional liposomal formulation or soluble CNDAC. These results suggest that DPP-CNDAC/CH liposomes are useful for metastatic pulmonary cancer.