Photodynamic Inactivation of Bacteria Using Novel Electrogenerated Porphyrin-Fullerene C sub( 60) Polymeric Films

A porphyrin-fullerene C... dyad (TCP-C...) substituted by carbazoyl groups was used to obtain electrogenerated polymeric films on optically transparent indium tin oxide (ITO) electrodes. This approach produced stable and reproducible polymers, holding fullerene units. The properties of this film were compared with those formed by layers of TCP/TCP-C... and TCP/ZnTCP. Absorption spectra of the films presented the Soret and Q bands of the corresponding porphyrins. The TCP-C... film produced a high photodecomposition of 2,2-(anthracene-9,10-diyl)bis(methylmalonate), which was used to detect singlet molecular oxygen O... (...) production in water. In addition, the TCP-C... film induced the reduction of nitro blue tetrazolium to diformazan in the presence of NADH, indicating the formation of superoxide anion radical. Moreover, photooxidation of L-tryptophan mediated by TCP-C... films was found in water. In biological media, photoinactivation of Staphylococcus aureus was evaluated depositing a drop with 2.5 x 10... cells on the films. After 30 min irradiation, no colony formation was detected using TCP-C... or TCP/TCP-C... films. Furthermore, photocytotoxic activity was observed in cell suspensions of S. aureus and Escherichia coli. The irradiated TCP-C... film produced a 4 log decrease of S. aureus survival after 30 min. Also, a 4 log reduction of E. coli viability was obtained using the TCP-C... film after 60 min irradiation. Therefore, the TCP-C... film is an interesting and versatile photodynamic active surface to eradicate bacteria. (ProQuest: ... denotes formulae/symbols omitted.)