A flexible nano carrier for siRNA delivery into tumor

For effective tumor therapy by small interfering RNAs (siRNA), the siRNA is required to be delivered into the inside of tumor tissue. However, since existing many carriers for siRNA delivery are rigid particles, it is difficult to penetrate into tumor tissue. Thus, we hypothesized that a flexible carrier of siRNA should enter to deep region of tumor. In the present study, we constructed the flexible nano carrier (FNC) consisting of a flexible wick structure, which was prepared by mixing of siRNA with poly-L-lysine (PLL), coated with lipid membrane. The FNC containing anti-luciferase siRNA showed significant RNAi effect in mono-layered culture cancer cells expressing luciferase. Moreover, the FNC penetrated into the spheroid of cancer cells. Consequently, we developed a novel siRNA carrier, FNC, penetrable to tumor tissue.