title: Photodynamic properties and photoantimicrobial action of electrochemically generated porphyrin polymeric films.
abstract: Spectroscopic and photodynamic properties of polymeric films bearing porphyrin units have been studied in both solution containing photooxidizable substrates and in vitro on Escherichia coli and Candida albicans microorganisms. The films were formed by electrochemical polymerization of 5,10,15,20-tetra(4-N,N-diphenylaminophenyl)porphyrin (H2P-film) and its complex with Pd(II) (PdP-film) on optically transparent indium tin oxide (ITO) electrodes. Absorption spectroscopic studies show the characteristic Soret and Q bands of the porphyrin in the visible region and a band at approximately 350 nm corresponding to the tetraphenylbenzidine units. Upon excitation, the H2P-film exhibits two bands of fluorescence emission from porphyrin, while it is not detected using PdP-film. The singlet molecular oxygen, O2(1Deltag), productions of these surfaces were evaluated using 9,10-dimethylanthracene in N,N-dimethylformamide. Also, the photodynamic activity was compared in solutions of L-tryptophan. Under these conditions, oxidation of these substrates takes place indicating an efficient photodynamic action of both polymeric films. In vitro investigations show that these films produce photosensitized inactivation of microbial cells in aqueous suspensions. These films exhibit a photosensitizing activity causing a approximately 3 log decrease of E. coil and approximately 2.5 log of C. albicans cellular survival after 30 min of irradiation with visible light. The photodynamic effect of the surfaces was also tested by growth delay experiments. The results indicate that porphyrins immobilized on electropolymeric films are interesting and versatile photodynamic surfaces to inactivate microorganisms in liquid suspensions.
authors.affiliation: Departamento de Química, Universidad Nacional de Río Cuarto, Río Cuarto, Agencia Postal Nro. 3, X5804BYA Río Cuarto, Córdoba, Argentina.
authors.forename: Matías D
authors.initials: MD
authors.lastname: Funes
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Caminos
authors.forename: M Gabriela
authors.initials: MG
authors.lastname: Alvarez
authors.forename: Fernando
authors.initials: F
authors.lastname: Fungo
authors.forename: Luis A
authors.initials: LA
authors.lastname: Otero
authors.forename: Edgardo N
authors.initials: EN
authors.lastname: Durantini
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development; D004563:Electrochemistry; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development; D010777:Photochemistry; D011108:Polymers / Q000737:chemistry* / Q000494:pharmacology; D011166:Porphyrins / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D011108:Polymers; D011166:Porphyrins