Ricin B-chain promotes the internalisation of liposomal contents into rat hepatoma cells.

Ricin B-chain covalently attached to liposomes has been shown to promote the binding of the liposomes to rat hepatoma cells through its galactosyl binding site. Internalisation of the bound liposomes is demonstrated by the cytotoxicity of methotrexate-containing liposomes, the transfection of cells with targeted liposomes containing pSV2-neo DNA and the intracellular activity of an enzyme encapsulated in liposomes targeted with the ricin B-chain.