An aminated polyamine having the formula: or its possible stereoisomers or a salt thereof with a pharmaceutically acceptable acid wherein: R1 and R4 may be the same or different and are alkyl, aryl, aryl alkyl or cycloalkyl, optionally having an alkyl chain interrupted by at least one etheric oxygen atom; R2 and R3 may be the same or different and are R1, R4 or H; N1, N2, N3 and N4 are nitrogen atoms capable of protonation at physiological pH's; ALK1, ALK2 AND ALK3 may be the same or different and are straight or branched chain alkylene bridging groups having 1 to 4 carbon atoms which effectively maintain the distance between the nitrogen atoms such that the polyamine: (i) is capable of uptake by a target cell upon administration of the polyamine to a human or non-human animal or is capable of binding to at least one polyamine site of a receptor located within or on the surface of a cell upon administration of the polyamine to a human or non-human animal; and (ii) upon uptake by the target cell, competitively binds via an electrostatic interaction between the positively charged nitrogen atoms to biological counter-anions; the polyamine, upon binding to the biological counter-anion in the cell, functions in a manner biologically different than the intracellular polyamines; and further wherein at least one of said bridging groups ALK1, ALK2 and ALK3 contains at least one —CH(NRH)— group which is not alpha- to either of the nitrogen atoms and R is H, alkyl, acyl or sulfonyl.