Influence of copper (II) ions and its derivatives on radiosensitivity of Escherichia coli

In an attempt to explore potential of Cu(II) ions and its synthetic aminocarboxylic complexes as radiosensitizers in cellular systems, we sought to follow the influence of these substances on radiosensitivity of Escherichia coli K12 strain. Cytotoxicity of Cu(II) ions could be reduced significantly by sequestering with the suitable aminocarboxylic chelating agents. The dose dependent cell survival, in the absence and the presence of additives, was monitored by cell inactivation assay. Extent of DNA damage in the process of radiosensitization was determined using fluorimetric technique. It was observed that Cu2+ ions radiosensitize the cells. Among the three complexes studied, Cu-NTA (nitrilo triacetic acid) can enter into cells and can radiosensitize the same. Structure of metal complex and the presence of electron affinic site(s) play an important role in its cellular incorporation and to function as radiosensitizer. The present study indicates that Cu-NTA may be considered a suitable model for development of radiosensitizing metal complexes.