Synthesis and photodynamic effect of new highly photostable decacationically armed [60]- and [70]fullerene decaiodide monoadducts to target pathogenic bacteria and cancer cells

摘要

Novel water-soluble decacationically armed C _(60) and C _(70) decaiodide monoadducts, C _(60)- and C _(70)[> M(C _3N _6 ~+C _3) _2], were synthesized, characterized, and applied as photosensitizers and potential nano-PDT agents against pathogenic bacteria and cancer cells. A high number of cationic charges per fullerene cage and H-bonding moieties were designed for rapid binding to the anionic residues displayed on the outer parts of bacterial cell walls. In the presence of a high number of electron-donating iodide anions as parts of quaternary ammonium salts in the arm region, we found that C _(70)[>M(C _3N _6 ~+C _3) _2] produced more HO "~￠ than C _(60)[> M(C _3N _6 ~+C _3) _2], in addition to O _2~1. This finding offers an explanation of the preferential killing of Gram-positive and Gram-negative bacteria by C _(60)[>M(C _3N _6 ~+C _3) _2] and C _(70)[>M(C _3N _6 ~+C _3) _2], respectively. The hypothesis is that O _2~1 can diffuse more easily into porous cell walls of Gram-positive bacteria to reach sensitive sites, while the less permeable Gram-negative bacterial cell wall needs the more reactive HO "~￠ to cause real damage.