Abstract: The present invention relates to a method for etching at least one surface of a plastic substrate, the method comprising steps (A) to (C), wherein step (B) comprises a contacting with a pre-treatment composition comprising one or more than one fluorine-free surface-active compound, and step (C) comprises a contacting with an etching composition comprising one or more than one manganese species, wherein after step (B) and prior to step (C) no rinsing is applied, and the etching composition is substantially free of, preferably does not comprise, fluorine-containing surface-active compounds.

Abstract: The present invention relates to the field of cancer therapy. Specifically, a chemotaxis fusion-receptor that directs bacteria towards tumors is disclosed. Further encompassed by the present invention is a bacterial cell that comprises at least one chemotaxis fusion-receptor and, preferably, a killing module for the destruction of tumor cells.