Read by QxMD icon Read

Photochemical & Photobiological Sciences

L A Betancourt-Buitrago, O E Ossa-Echeverry, J C Rodriguez-Vallejo, J M Barraza, N Marriaga, F Machuca-Martínez
The wastewater from gold exploitation is well known for the toxic nature of recalcitrant cyanide metallic complexes. In this work the selectivity in the photocatalytic degradation of gold mining wastewater (Fe(CN)63-) using suspended TiO2 with alcoholic and organic acid scavengers in a mini-CPC photoreactor with a 30 W UV-A LED as an artificial source of light was evaluated. The study was done in four stages: 1. load catalyst determination, 2. combination of scavengers in a typical photocatalytic degradation, 3...
September 17, 2018: Photochemical & Photobiological Sciences
Jordan Bouilloux, Oleksandr Yuschenko, Bogdan Dereka, Gianluca Boso, Andréj Babič, Hugo Zbinden, Eric Vauthey, Norbert Lange
Previously, we have shown that the use of a cyclopeptidic carrier could be of great interest for the design of fully characterized prodrugs for further use in photodynamic therapy. In order to further optimize the design, we decided to modify the highly quenched conjugate uPA-cPPP4/5 by co-loading a long-distance fluorescence quencher. For this purpose we tethered two black hole quenchers (BHQ3) together with two pheophorbide A moities onto the same PEGylated backbone and assessed the modified photophysical properties...
September 14, 2018: Photochemical & Photobiological Sciences
Jordan Bouilloux, Oleksandr Yuschenko, Bogdan Dereka, Gianluca Boso, Hugo Zbinden, Eric Vauthey, Andréj Babič, Norbert Lange
Herein, we report the synthesis of a new prodrug system consisting of regioselectively addressable functionalized templates bearing multiple pheophorbide A moieties for use in photodynamic therapy. These coupling reactions were achieved using copper-free "click" chemistry, namely a strain-promoted azide-alkyne cycloaddition. This new design was used to obtain well-defined quenched photosensitizer prodrugs with perfect knowledge of the number and position of loaded photosensitizers, providing structures bearing up to six photosentitizers and two PEG chains...
September 14, 2018: Photochemical & Photobiological Sciences
Venkatesh Gude, Duttanjali Rout, Mruganka Kumar Panigrahi, Kumar Biradha
Fluorescent four-ring symmetrical/unsymmetrical molecules containing alkyl chains of a varied number of -CH2- groups with a bent-core have been synthesized to explore their liquid crystalline (LC) and photophysical properties. Some of these molecules depending upon their alkyl chain length were found to exhibit B1 and B7 liquid crystalline phases and are characterized by various analytical techniques such as FT-IR, 1H NMR, mass, POM, DSC, single crystal XRD, etc. Crystal structure determination reveals the hydrogen bonded enol form of these molecules with non-planar bent-molecular geometry...
September 13, 2018: Photochemical & Photobiological Sciences
Hiroshi Yao, Hikaru Minami, Tomohito Funada
We successfully synthesize fluorescent organic nanoparticles of a Lewis-pair consisting of an amino-type hydrogen-bonding molecule (Lewis base) and a borinate derivative (Lewis acid). 2-(2'-Aminophenyl)benzothiazole (o-ABT) is chosen as the fluorophore. This molecule has a transferable proton in the amino group, but it does not exhibit ESIPT (excited-state intramolecular proton transfer) reaction in solution and thus shows a single normal emission solely from the enamine form. Organic nanoparticles are prepared by the reprecipitation method in which the fluorophore (o-ABT) in conjunction with a Lewis acid (diphenylborinic anhydride; DPBA) dissolved in a good solvent is rapidly injected into water under sonication...
September 10, 2018: Photochemical & Photobiological Sciences
Alexander V Liubimov, Olga V Venidiktova, Tatyana M Valova, Andrey I Shienok, Liubov S Koltsova, Galina V Liubimova, Leonid D Popov, Natalia L Zaichenko, Valery A Barachevsky
A novel hybrid compound whose molecule includes the photochromic spiropyran fragment and two fluorophores - coumarin and salicylideneimine - was synthesized by the reaction of two equivalents of 8-formyl-7-hydroxy-4-methylcoumarin with 5-amino-1,3,3-trimethyl-2-methyleneindoline. Its spectral-kinetic and fluorescence properties were studied in comparison with model compounds - 7-hydroxy-4-methyl-coumarin, spiropyran of the coumarin type, and azomethinocoumarin in toluene and ethanol. It was shown that the hybrid compound exhibited photochromic transformations in both solvents...
September 7, 2018: Photochemical & Photobiological Sciences
L Charbonnière, S Haacke
No abstract text is available yet for this article.
September 6, 2018: Photochemical & Photobiological Sciences
Gabriela Alves da Collina, Fernanda Freire, Thabata Paulino da Costa Santos, Natalia Gesse Sobrinho, Simone Aquino, Renato Araújo Prates, Daniela de Fátima Teixeira da Silva, Anna Carolina Ratto Tempestini Horliana, Christiane Pavani
Methylene Blue (MB) has been widely used in antimicrobial Photodynamic Therapy (aPDT), however, the mechanisms of action (Type I or Type II) are defined by its state of aggregation. In this sense, the identification of the relationships between aggregation, the mechanisms of action and the effectiveness against microorganisms, as well as the establishment of the means and the formulations that may favor the most effective mechanisms, are essential. Thus, the objective of this study was to assess the in vitro aPDT efficacies against Candida albicans, by using MB in vehicles which may influence the aggregation and present an oral formulation (OF) containing MB, to be used in clinical aPDT procedures...
September 5, 2018: Photochemical & Photobiological Sciences
Farhan Sadiq, Jianzhang Zhao, Mushraf Hussain, Zhijia Wang
The effect of thienyl substitution on the intersystem crossing (ISC) of a few arenes was studied using steady state and time-resolved transient absorption and emission spectroscopies, as well as DFT/TDDFT computations. We found that the phenyl and thienyl substituents generally induce red-shifted absorptions for the chromophores, and the DFT/TDDFT computations show that the red-shifted absorption and emission are due to the increased HOMO and the reduced LUMO energy levels. Nanosecond transient absorption spectra indicate the formation of a triplet state, the triplet state lifetime is up to 282 μs, and the singlet oxygen quantum yields (ΦΔ) are up to 60%...
September 5, 2018: Photochemical & Photobiological Sciences
K Bilici, A Muti, F Demir Duman, A Sennaroğlu, H Yağcı Acar
The use of superparamagnetic iron oxide nanoparticles (SPIONs) as a sensitizer in photothermal therapy (PTT) is relatively new and the origin of such a phenomenon is not known. Usually, large crystals and aggregated particles are preferred in the literature, suggesting that these increase the absorbance of particles at the irradiation wavelength, and hence, provide a larger temperature increase. This study has two major goals: identification of the key factors that affect the photo-induced temperature increase in well-controlled experiments and the influence of laser irradiation on nanoparticle properties...
August 31, 2018: Photochemical & Photobiological Sciences
Cyril Ringot, Naïma Saad, Frédérique Brégier, Philippe Bressollier, Evelyne Poli, Vincent Chaleix, Tan Sothea Ouk, Vincent Sol
We report the preparation of a cellulose fabric bearing derivative protoporphyrin IX units covalently attached to the cellulose backbone of a fabric. Ce(IV) redox system radical polymerization was used to polymerize methacrylic acid (MAA) onto a cotton material and to obtain cotton-g-polyMAA. Attachment of the photosensitizer, a protoporphyrin IX (PpIX) amino derivative, on cotton-g-polyMAA was realized successfully by a classical peptidic covalent link. The modified surfaces were characterized by ATR-FTIR, DRUV, TGA, and SEM methods...
August 31, 2018: Photochemical & Photobiological Sciences
Shun Gao, Hailiang Zhou, Sumei Cui, Hai Shen
Photothermal therapy (PTT) is providing new opportunities for killing cancer cells. In this work, we introduce a new nanomedicine based on spherical MoS2 nanoparticles for PTT treatment of tumors, prepared using "green" bottom-up technology. To increase water solubility and avoid rapid clearance by the reticuloendothelial system, polyethylene glycol (PEG) was used to coat them. These MoS2-PEG nanospheres with an appropriate size (∼100 nm) exhibit high photothermal conversion efficiency (26.7%). In vitro cellular studies revealed that the MoS2-PEG nanospheres showed negligible cytotoxicity...
August 24, 2018: Photochemical & Photobiological Sciences
Aurore Fraix, Salvatore Sortino
Combination of photodynamic therapy (PDT) with other treatment modalities is emerging as one of the most suitable strategies to increase the effectiveness of therapeutic action on cancer and bacterial diseases and to minimize side effects. This approach aims at exploiting the additive/synergistic effects arising from multiple therapeutic species acting on different mechanistic pathways. The coupling of PDT with photocontrolled release of nitric oxide (NO) through the appropriate assembly of PDT photosensitizers (PSs) and NO photodonors (NOPDs) may open up intriguing avenues towards new and still underexplored multimodal therapies not based on "conventional" drugs but entirely controlled by light stimuli...
August 24, 2018: Photochemical & Photobiological Sciences
Alexander Müller, Annegret Preuß, Tobias Bornhütter, Isabell Thomas, Andrea Prager, Agnes Schulze, Beate Röder
Polymer membranes are powerful filtration tools in medicine and water treatment. Their efficiency and operational lifetime is limited by biofouling caused by microorganisms. This study describes the development of photodynamical active antimicrobial polymer membranes in a one-pot functionalization step using a well-known photosensitizer (PS). Commercially available polyethersulfone (PES) membranes for microfiltration were doped with the polycationic PS TMPyP using electron beam irradiation. These membranes were characterized in terms of binding stability and quantification of the PS and membrane morphology...
August 24, 2018: Photochemical & Photobiological Sciences
Paula García Calavia, Gordon Bruce, Lluïsa Pérez-García, David A Russell
Gold nanoparticles (AuNPs) have been extensively studied within biomedicine due to their biocompatibility and low toxicity. In particular, AuNPs have been widely used to deliver photosensitiser agents for photodynamic therapy (PDT) of cancer. Here we review the state-of-the-art for the functionalisation of the gold nanoparticle surface with both photosensitisers and targeting ligands for the active targeting of cancer cell surface receptors. From the initial use of the AuNPs as a simple carrier of the photosensitiser for PDT, the field has significantly advanced to include: the use of PEGylated modification to provide aqueous compatibility and stealth properties for in vivo use; gold metal-surface enhanced singlet oxygen generation; functionalisation of the AuNP surface with biological ligands to specifically target over-expressed receptors on the surface of cancer cells and; the creation of nanorods and nanostars to enable combined PDT and photothermal therapies...
August 17, 2018: Photochemical & Photobiological Sciences
Anne E Cust, Kriti Mishra, Marianne Berwick
Melanoma rates have increased in populations that are mainly European. The main etiologic factor is ultraviolet radiation, from the sun as well as artificial tanning devices. Host factors such as skin color, number of nevi, hair and eye color and tanning ability are critical factors in modifying an individual's response to the sun. Genetic factors interact with host factors and environmental factors to increase risk. This review summarizes our current knowledge of environment and genetics on melanoma risk and on gene-environment interaction...
August 16, 2018: Photochemical & Photobiological Sciences
Zhan Zhou, Yuhui Zheng, Cheng Cheng Zhang, Jinwei Gao, Yiping Tang, Qianming Wang
Carbonaceous materials have long been developed to utilize "nano-spaces" and numerous guest species could be encapsulated. A remarkable fluorescence difference has been observed after newly designed pyropheophorbide-a-appended carbon nanohorns were incorporated in a cellular medium and confocal microscopy was employed for the determination of the intracellular localization. Our study supported the role of carbon nanohorns as carriers of photodynamic therapy (PDT) agents and their heating behavior was discussed...
August 16, 2018: Photochemical & Photobiological Sciences
B Habermeyer, R Guilard
Photodynamic therapy is an innovative approach to treat diverse cancers and diseases that involves the use of photosensitizing agents along with light of an appropriate wavelength to generate cytotoxic reactive oxygen species. Among the collection of potential dye candidates, porphyrinoids (i.e. porphyrins, chlorins, and phthalocyanines) are probably the most promising photosensitizers for PDT applications. This review shows the great potential of these derivatives for their industrial development in the field of health through different applications in photodynamic therapy (PDT), photoimmunotherapy (PIT), ophthalmology, dermatology and photodynamic inactivation (PDI)...
August 15, 2018: Photochemical & Photobiological Sciences
Lei Wang, Mayu Fujii, Minoru Yamaji, Hideki Okamoto
The absorption and fluorescence spectra of a series of 1,8-naphthalimide derivatives incorporating the amino functionality at the 2-, 3- and 4-positions of the naphthalene ring (2APNI, 3APNI and 4APNI, respectively) were systematically investigated in various solvents and in the solid state. The fluorescence spectra of 2APNI were insensitive to solvent polarity and intermolecular hydrogen-bonding even in a protic medium such as methanol. Thus, 2APNI displayed blue fluorescence with a moderate fluorescence quantum yield (λFmax = 420-445 nm, ΦF 0...
August 15, 2018: Photochemical & Photobiological Sciences
Alfonso Blázquez-Castro, Thomas Breitenbach, Peter R Ogilby
Reactive oxygen species, ROS, are acknowledged signaling molecules in cellular processes. Singlet molecular oxygen, O2(a1Δg), is one ROS that can initiate cell responses that range from death to proliferation. To better understand the mechanisms involved, it is necessary to further investigate cell response to the "dose" of O2(a1Δg) that has been selectively produced at the expense of other ROS. In this context, dose refers not just to the amount of O2(a1Δg) produced, but also to the subcellular spatial domain in which it is produced...
August 10, 2018: Photochemical & Photobiological Sciences
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"