Optical sensors based on the quenching of the luminescence of platinum(II)octaethylporphyrin (PtOEP) encapsulated in nanofiber polymeric membranes were prepared by electrospinning. The samples were characterized using scanning electron microscopy, confocal luminescence microscopy, absorption spectroscopy, and steady-state and time-resolved luminescence techniques. The properties of the sensors were changed by the selection of different polymeric membranes using polycaprolactone, polystyrene, polyurethane Tecophilic, and poly(vinylidene fluoride-co-hexafluoropropylene) polymers. Among them, biodegradable and biocompatible sensors prepared from polycaprolactone with a high oxygen diffusion coefficient exhibited a fast response time (0.37 s), recovery time (0.58 s), high sensitivity (maximum I 0 /I ratio = 52), reversible luminescent response, and linear Stern-Volmer quenching over the whole range of oxygen contents in both the gas atmosphere and aqueous media. Moreover, the proposed sensors exhibited high antibacterial properties, resulting in self-sterilization character of the membrane surface due to the photogeneration of singlet oxygen. This dual character can find application in the biomedical field, where both properties (oxygen sensing and self-sterilization) can be acquired from the same material.

• Publication type
• Journal Article MeSH

We have prepared photoactive multifunctional nanofiber membranes via the simple electrospinning method. The antibacterial and photocatalytic properties of these materials are based on the generation of singlet oxygen formed by processes photosensitized by the tetraphenylporphyrin encapsulated in the nanofibers. The addition of magnetic features in the form of magnetic maghemite (γ-Fe2O3) nanoparticles stabilized by polyethylenimine enables additional functionalities, namely, the postirradiation formation of hydrogen peroxide and improved photothermal properties. This hybrid material allows for remote manipulation by a magnetic field, even in hazardous and/or highly microbial contaminant environments.

• Publication type
• Journal Article MeSH

Prion disorders, or transmissible spongiform encephalophaties (TSE), are fatal neurodegenerative diseases affecting mammals. Prion-infectious particles comprise of misfolded pathological prion proteins (PrPTSE). Different TSEs are associated with distinct PrPTSE folds called prion strains. The high resistance of prions to conventional sterilization increases the risk of prion transmission in medical, veterinary and food industry practices. Recently, we have demonstrated the ability of disulfonated hydroxyaluminum phthalocyanine to photodynamically inactivate mouse RML prions by generated singlet oxygen. Herein, we studied the efficiency of three phthalocyanine derivatives in photodynamic treatment of seven mouse adapted prion strains originating from sheep, human, and cow species. We report the different susceptibilities of the strains to photodynamic oxidative elimination of PrPTSE epitopes: RML, A139, Fu-1 > mBSE, mvCJD > ME7, 22L. The efficiency of the phthalocyanine derivatives in the epitope elimination also differed (AlPcOH(SO3)2 > ZnPc(SO3)1-3 > SiPc(OH)2(SO3)1-3) and was not correlated to the yields of generated singlet oxygen. Our data suggest that the structural properties of both the phthalocyanine and the PrPTSE strain may affect the effectiveness of the photodynamic prion inactivation. Our finding provides a new option for the discrimination of prion strains and highlights the necessity of utilizing range of prion strains when validating the photodynamic prion decontamination procedures.

• Keywords
• PDI, PrP, TSE, photodynamic, phthalocyanine, prion, prion inactivation, protein folding, singlet oxygen, strain,
• MeSH
• Photochemotherapy methods   MeSH
• Photosensitizing Agents pharmacology   MeSH
• Indoles chemistry   MeSH
• Humans MeSH
• Brain drug effects   metabolism   radiation effects   MeSH
• Mice MeSH
• Organometallic Compounds chemistry   MeSH
• Sheep MeSH
• Oxidation-Reduction MeSH
• Prion Proteins metabolism   MeSH
• Prion Diseases drug therapy   metabolism   pathology   MeSH
• Protein Folding MeSH
• Singlet Oxygen MeSH
• Cattle MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Cattle MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Photosensitizing Agents MeSH
• Indoles MeSH
• Organometallic Compounds MeSH
• Prion Proteins MeSH
• Singlet Oxygen MeSH
• zinc(II) phthalocyanine trisulfonic acid MeSH Browser

We prepared antibacterial polystyrene nanoparticles (NPs) with natural photosensitizers from chlorophyll (Chl) extract via a simple nanoprecipitation method using the same solvent for dissolution of the polystyrene matrix and extraction of Chls from spinach leaves. A high photo-oxidation and antibacterial effect was demonstrated on Escherichia coli and was based on the photogeneration of singlet oxygen O2(1Δg), which was directly monitored by NIR luminescence measurements and indirectly verified using a chemical trap. The photoactivity of NPs was triggered by visible light, with enhanced red absorption by Chls. To reduce the quenching effect of carotenoids (β-carotene, lutein, etc.) in the Chl extract, diluted and/or preirradiated samples, in which the photo-oxidized carotenoids lose their quenching effect, were used for preparation of the NPs. For enhanced photo-oxidation and antibacterial effects, a sulfonated polystyrene matrix was used for preparation of a stable dispersion of sulfonated NPs, with the quenching effect of carotenoids being suppressed.

• Publication type
• Journal Article MeSH

Polymeric polyurethane nanofabrics doped by zinc tetraphenylporphyrin (ZnTPP) and/or zinc phthalocyanine (ZnPc) photosensitizers were prepared by the electrospinning method and characterized by microscopic methods, steady-state and time-resolved fluorescence, and absorption spectroscopy. Nanofabrics doped by both ZnTPP and ZnPc efficiently harvest visible light to generate triplet states and singlet oxygen O2(1Delta(g)) with a lifetime of about 15 micros in air atmosphere. The energy transfer between the excited singlet states of ZnTPP and ground states of ZnPc is described in details. All nanofabrics have bactericidal surfaces and photooxidize inorganic and organic substrates. ZnTPP and ZnPc in the polyurethane nanofabrics are less photostable than incorporated free-base tetraphenylporphyrin (TPP).

• MeSH
• Time Factors MeSH
• Spectrometry, Fluorescence MeSH
• Photochemistry MeSH
• Photosensitizing Agents chemistry   MeSH
• Indoles chemistry   MeSH
• Isoindoles MeSH
• Oxygen chemistry   MeSH
• Metalloporphyrins chemistry   MeSH
• Molecular Structure MeSH
• Nanostructures chemistry   MeSH
• Organometallic Compounds chemistry   MeSH
• Oxidation-Reduction MeSH
• Polyurethanes chemical synthesis   chemistry   MeSH
• Surface Properties MeSH
• Zinc Compounds MeSH
• Spectrophotometry, Ultraviolet MeSH
• Particle Size MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Photosensitizing Agents MeSH
• Indoles MeSH
• Isoindoles MeSH
• Oxygen MeSH
• Metalloporphyrins MeSH
• Organometallic Compounds MeSH
• Polyurethanes MeSH
• Zinc Compounds MeSH
• zinc tetraphenylporphyrin MeSH Browser
• Zn(II)-phthalocyanine MeSH Browser