DNA binding and biological studies of some novel water-soluble polymer-copper(II)-phenanthroline complexes

Some novel water-soluble polymer-copper(II)-phenanthroline complex samples, [Cu(phen)(2)(BPEI)]Cl-2 center dot 4H(2)O (phen = 1,10-phenanthroline, BPEI = branched polyethyleneimine), with different degrees of copper complex content in the polymer chain have been prepared by ligand substitution method in water-ethanol medium and characterized by infrared, UV-visible, EPR spectral and elemental analysis methods. The binding of these complex samples with DNA has been investigated by electronic absorption spectroscopy, emission spectroscopy and gel retardation assay. Electrostatic interactions between DNA molecule and polymer-copper(II) complex molecule containing many high positive charges have been observed. Besides these ionic interactions, van der Waals interactions, hydrogen bonding and other partial intercalation binding modes may also exist in this system. The polymer-copper(II) complex with higher degree of copper complex content was screened for its antimicrobial activity and antitumor activity. (C) 2007 Elsevier Masson SAS. All rights reserved.