title: Singlet oxygen generation in porphyrin-doped polymeric surface coating enables antimicrobial effects on Staphylococcus aureus.
abstract: Surfaces can be coated with photosensitizer molecules, which generate singlet oxygen ((1)O2) when the surface is exposed to light. (1)O2 may diffuse from the coating and has the potential to kill microorganisms present on the surface. In the present study a derivative of the meso-tetraphenylporphyrin (TPP) was immobilized onto polyurethane (PU) after being sprayed and polymerized as a thin layer onto poly-methylmethacrylate (PMMA). PU is gas permeable and thus a sufficient amount of oxygen reaches the photosensitizer in this coating. The surface generation of (1)O2 and its diffusion were investigated by detecting its luminescence at 1270 nm and a tri-iodide assay. Antimicrobial photodynamic surface effects were tested on Staphylococcus aureus. The spectrally resolved detection of (1)O2 luminescence yielded a clear peak at 1275 nm. The time-resolved luminescence showed multi-exponential decay, revealing rise and decay times in the range of 5-2 × 10(2)μs. The photodynamic inactivation of S. aureus was monitored at different photosensitizer concentrations and radiant exposures of light. A photodynamic killing of >99.9% (>3log10-steps) was achieved within an irradiation time of 30 min. The photodynamic killing on the bioactive surface confirmed the antimicrobial effect of (1)O2 that was generated in the PU-coating and reached the bacteria by diffusion.
authors.affiliation: Department of Dermatology, Regensburg University Hospital, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany. ariane.felgentraeger@klinik.uni-regensburg.de.
authors.forename: Ariane
authors.initials: A
authors.lastname: Felgenträger
authors.forename: Tim
authors.initials: T
authors.lastname: Maisch
authors.forename: Andreas
authors.initials: A
authors.lastname: Späth
authors.forename: Josef A
authors.initials: JA
authors.lastname: Schröder
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Bäumler
mesh_terms: D000327:Adsorption; D000890:Anti-Infective Agents / Q000138:chemical synthesis / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D020099:Coated Materials, Biocompatible / Q000737:chemistry* / Q000494:pharmacology*; D008027:Light; D008422:Materials Testing; D017319:Photosensitizing Agents / Q000737:chemistry / Q000494:pharmacology*; D011140:Polyurethanes / Q000737:chemistry*; D011166:Porphyrins / Q000737:chemistry* / Q000528:radiation effects; D026082:Singlet Oxygen / Q000737:chemistry / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000502:physiology*
chemical_list: D000890:Anti-Infective Agents; D020099:Coated Materials, Biocompatible; D017319:Photosensitizing Agents; D011140:Polyurethanes; D011166:Porphyrins; D026082:Singlet Oxygen