Lixin Cao, Dongquan Bi, Wei Fan, Juntian Xu, John Beardall, Kunshan Gao, Yaping Wu
Under global change scenarios, the sea surface temperature is increasing steadily along with other changes to oceanic environments. Consequently, marine diatoms are influenced by multiple ocean global change drivers. We hypothesized that temperature rise mediates the responses of polar and temperate diatoms to UV radiation (UVR) to different extents, and exposed the temperate centric diatoms, Thalassiosira weissflogii and Skeletonema costatum, and a polar pennate diatom Entomoneis sp., to warming (+5°C) for 10 days, then performed short-term incubations under different radiation treatments with or without UVR...
August 1, 2023: Photochemistry and Photobiology
Shruti Vig, Brandon Gaitan, Lucas Frankle, Yu Chen, Rosalie Elespuru, T Joshua Pfefer, Huang-Chiao Huang
Various fluorescence imaging agents are currently under clinical studies. Despite significant benefits, phototoxicity is a barrier to the clinical translation of fluorophores. Current regulatory guidelines on medication-based phototoxicity focus on skin effects during sun exposure. However, with systemic and local administration of fluorophores and targeted illumination, there is now possibility of photochemical damage to deeper tissues during intraoperative imaging procedures. Hence, independent knowledge regarding phototoxicity is required to facilitate the development of fluorescence imaging products...
July 26, 2023: Photochemistry and Photobiology
David Kessel
Comparison of MTT versus clonogenic effects of photodynamic therapy in MCF-7c3 breast cancer cells in culture. Left: MTT data; right clonogenic data. A collection of photosensitizers was used to produce these results.
July 24, 2023: Photochemistry and Photobiology
Carine Jacques, Daniel Bacqueville, Emilien L Jamin, Martine Maitre, Cécile Delsol, Aimée Simcic-Mori, Pascale Bianchi, Anais Noustens, Isabelle Jouanin, Laurent Debrauwer, Sandrine Bessou-Touya, Eggert Stockfleth, Hélène Duplan
A reconstructed human epidermal model (RHE) colonized with human microbiota and sebum was developed to reproduce the complexity of the skin ecosystem in vitro. The RHE model was exposed to simulated solar radiation (SSR) with or without SPF50+ sunscreen (with UVB, UVA, long-UVA, and visible light protection). Structural identification of discriminant metabolites was acquired by nuclear magnetic resonance and metabolomic fingerprints were identified using reverse phase-ultra high-performance liquid chromatography-high resolution mass spectrometry, followed by pathway enrichment analysis...
July 24, 2023: Photochemistry and Photobiology
Midori Shirato, Yuma Takida, Taro Kanno, Hiroshi Matsuura, Yoshimi Niwano, Hiroaki Minamide, Keisuke Nakamura
The effect of terahertz (THz) radiation has been studied in medicine. However, there is a lack of scientific information regarding its possible mutagenicity. Therefore, the present study aimed to assess the mutagenicity of 1.6 THz laser irradiation. The Ames test was conducted using five bacterial tester strains. The bacteria were subjected to (i) 1.6 THz laser irradiation at 3.8 mW/cm2 for 60 min using a tabletop THz pulse laser system, (ii) ultraviolet irradiation, (iii) treatment with positive control chemicals (positive control) or (iv) treatment with the solvent used in the positive control (negative control)...
July 21, 2023: Photochemistry and Photobiology
Alina Bekmukhametova, Anu Antony, Catriona Halliday, Sharon Chen, Chun-Hoong Ho, Mir Muhammad Nasir Uddin, Leonardo Longo, Christian Pedrinazzi, Laurel George, Richard Wuhrer, Simon Myers, Damia Mawad, Jessica Houang, Antonio Lauto
Rose bengal (RB) solutions coupled with a green laser have proven to be efficient in clearing resilient nail infections caused by Trichophyton rubrum in a human pilot study and in extensive in vitro experiments. Nonetheless, the RB solution can become diluted or dispersed over the tissue and prevented from penetrating the nail plate to reach the subungual area where fungal infection proliferates. Nanoparticles carrying RB can mitigate the problem of dilution and are reported to effectively penetrate through the nail...
July 21, 2023: Photochemistry and Photobiology
Kazi Md Mahabubur Rahman, Barbara A Foster, Youngjae You
Photodynamic therapy (PDT) initially employed red light, which caused some patients to experience permanent bladder contractions. PDT using the FDA-approved drug hexaminolevulinate (HAL), which produces protoporphyrin IX (PpIX) in the tumor, showed some promise but has low efficacy in treating non-muscle-invasive bladder cancer (NMIBC). We developed singlet oxygen-activatable prodrugs of two anticancer drugs, paclitaxel and mitomycin C, to enhance the antitumor effect of PpIX-PDT without producing systemic side effects, by promoting only local release of the active chemotherapeutic agent...
July 20, 2023: Photochemistry and Photobiology
Ravindra K Shukla, Rajesh K Yadav, V L Gole, Chae Yeong Na, Gyoung Hwa Jeong, Satyam Singh, Jin-Ook Baeg, Myong Yong Choi, Navneet Kumar Gupta, Tae Wu Kim
Aloe vera-derived graphene (ADG) coupled system photocatalyst, mimicking natural photosynthesis, is one of the most promising ways for converting solar energy into ammonia (NH3 ) and nicotinamide adenine dinucleotide (NADH) that have been widely used to make the numerous chemicals such as fertilizer and fuel. In this study, we report the synthesis of the aloe vera-derived graphene-coupled phenosafranin (ADGCP) acting as a highly efficient photocatalyst for the generation of NH3 and regeneration of NADH from nitrogen (N2 ) and oxidized form of nicotinamide adenine dinucleotide (NAD+ )...
July 17, 2023: Photochemistry and Photobiology
Brian Ospina-Calvo, Eduardo De Gerónimo, Fernando D Villarruel, Virgina C Aparicio, Lorena Ashworth, Rosa Erra-Balsells, Franco M Cabrerizo
This study reports valuable information regarding the presence and concentration of a series of photoactive β-carboline (βCs) alkaloids (norharmane, harmane, harmine, harmol, harmaline, and harmalol) and their distribution across the floral age and organs of Passiflora caerulea. UHPLC-MS/MS data reported herein reveal that the βCs' content ranged from 1 to 110 μg kg-1 , depending on the floral organ and age. In certain physiologically relevant organs, such as anthers, βCs' content was one order of magnitude higher than in other organs, suggesting a special role for βCs in this specific organ...
July 13, 2023: Photochemistry and Photobiology
Xue-Ping Chang, Jie-Lei Wang, Ling-Ya Peng, Xu-Jiang Cen, Bo-Wen Yin, Bin-Bin Xie
Previously, the MS-CASPT2 method was performed to study the static and qualitative photophysics of tellurium-substituted cytosine (TeC). To get quantitative information, we used our recently developed QTMF-FSSH dynamics method to simulate the excited-state decay of TeC. The CASSCF method was adopted to reduce the calculation costs, which was confirmed to provide reliable structures and energies as those of MS-CASPT2. A detailed structural analysis showed that only 5% trajectories will hop to the lower triplet or singlet state via the twisted (S2 /S1 /T2 )T intersection, while 67% trajectories will choose the planar intersections of (S2 /S1 /T3 /T2 /T1 )P and (S2 /S1 /T2 /T1 )P but subsequently become twisted in other electronic states...
July 12, 2023: Photochemistry and Photobiology
Gülşah Gümrükçü Köse, Ali Erdoğmuş
To treat a life-threatening disease like cancer, photodynamic therapy (PDT) and sonodynamic therapy (SDT) methods were combined into sono-photodynamic therapy (SPDT) as an effective therapeutic solution. Each day, the usage of phthalocyanine sensitizers increases in the therapeutic applications as they have the ability to produce more reactive oxygen species. In this context, a new diaxially silicon phthalocyanine sensitizer, containing triazole and tert-butyl groups, was synthesized. After elucidating the structure of the complex with elemental analysis, FT-IR, UV-Vis, MALDI-TOF MS and 1 H NMR, its photophysical, photochemical and sono-photochemical properties were examined...
July 10, 2023: Photochemistry and Photobiology
Lara Martinez-Fernandez, Roberto Improta
We here study the effect that a lowering of the pH has on the excited state processes of cytidine and a cytidine/cytidine pair in solution, by integrating time-dependent density functional theory and CASSCF/CASPT2 calculations, and including solvent by a mixed discrete/continuum model. Our calculations reproduce the effect of protonation at N3 on the steady-state infrared and absorption spectra of a protonated cytidine (CH+ ), and predict that an easily accessible non-radiative deactivation route exists for the spectroscopic state, explaining its sub-ps lifetime...
July 6, 2023: Photochemistry and Photobiology
Leonardo M F Oliveira, Danillo Valverde, Gustavo J Costa, Antonio Carlos Borin
9H- and 7H-2,6-Diaminopurine (26DAP) photoinduced events in vacuum were studied at the MS-CASPT2/cc-pVDZ level of theory. The S1 1 (ππ* La ) state is initially populated evolving barrierless towards its minimum energy structure, from where two photochemical events can take place in both tautomers. The first is the return of the electronic population to the ground state via the C6 conical intersection (CI-C6). The second involves an internal conversion to the ground through the C2 conical intersection (CI-C2)...
July 4, 2023: Photochemistry and Photobiology
A F Serain, A J Buitrago-Mejia, G C A de Souza, W R Corrêa, M E A Stefanello, M J Salvador
Photodynamic therapy (PDT) has been used for various purposes, including as an antitumor resource in a noninvasive therapy with minimal side effects. Sinningia magnifica (Otto & A. Dietr.) Wiehler is a rupicolous plant found in rock crevices in Brazilian tropical forests. Initial studies indicate the presence of phenolic glycosides and anthraquinones in species of the genus Sinningia (Generiaceae family). It is known that anthraquinones are natural photosensitizers with potential PDT applications. This led us to investigate the potential compounds of S...
July 3, 2023: Photochemistry and Photobiology
Krystian Mokrzyński, Olga Krzysztyńska-Kuleta, Mateusz Wojtala, Dawid Wnuk, Michał Sarna, Tadeusz Sarna
Continuous exposure of human skin to air pollution can result in a range of undesirable skin conditions. In our recent study, UV and visible light were found to increase cytotoxicity of fine particulate matter (PM2.5 ) against human keratinocytes. Since it is impossible to avoid exposure of human skin to PM2.5 , effective strategies are needed to reduce their damaging effects. l-ascorbic acid and resveratrol were tested as potential topical agents against pollution-related skin impairment. Although these agents were previously found to ameliorate PM-dependent damage, the effect of light and seasonal variation of particles were not previously studied...
June 26, 2023: Photochemistry and Photobiology
Dimitra Markovitsi
Guanine quadruplexes (GQs) are four-stranded DNA/RNA structures exhibiting an important polymorphism. During the past two decades, their study by time-resolved spectroscopy, from femtoseconds to milliseconds, associated to computational methods, shed light on the primary processes occurring when they absorb UV radiation. Quite recently, their utilization in label-free and dye-free biosensors was explored by a few groups. In view of such developments, this review discusses the outcomes of the fundamental studies that could contribute to the design of future optoelectronic biosensors using fluorescence or charge carriers stemming directly from GQs, without mediation of other molecules, as it is the currently the case...
June 26, 2023: Photochemistry and Photobiology
Andrej Hovan, Viktoria Pevna, Veronika Huntosova, Pavol Miskovsky, Gregor Bánó
Time-resolved phosphorescence detection was employed to determine the lifetime of singlet oxygen in live cells. Using hypericin as a photosensitizer, singlet oxygen was generated in U87MG glioblastoma cells. The phosphorescence of singlet oxygen was detected in aqueous cell suspensions following pulsed laser excitation. Our goal was to eliminate or reduce the problems associated with lifetime measurements in water-based cell suspensions. The apparatus enabled simultaneous singlet oxygen phosphorescence and transient absorption measurements, reducing uncertainty in lifetime estimation...
June 26, 2023: Photochemistry and Photobiology
Yanina Susana Minaberry, Federico Eugenio Svarc
The concept of modern human sun protection is no more than one hundred years, but real development of it, including protection against UVA + UVB radiation (and more recently also the IR and blue light), has been no more than 30 years. One fundamental issue while formulating sunscreens is the photostability of the UV filters, which is particularly feeble for the UVA. The gold standard for the determination of sunscreen UVA protection "in vitro" is ISO 24443:2021. Still, interlaboratory results are not as consistent as expected...
June 21, 2023: Photochemistry and Photobiology
Zahra Behroozi, Keihan Kookli, Alireza Ghadaksaz, Mahsa Motavaf, Seyedalireza Moghaddas Fazeli, Ali Motamed Nezhad, Fatemeh Ramezani, Atousa Janzadeh
Photobiomodulation therapy (PBMT) is converted to the most common analgesic treatment before the whole mechanism is yet to be discovered. This study for the first time was designed to investigate alternations of epigenetic factors after pain and PBMT. The CCI model was chosen to induce pain. Pain evaluation tests including plantar, acetone, von Frey, and pinch were done weekly. Then spinal cord tissue was isolated for evaluating mRNA expression of DNMT3a, HDAC1, and NRSF using RT-qPCR method, and protein expression factors of HDAC2 and DNMT3a using western blotting...
June 18, 2023: Photochemistry and Photobiology
Ceren Can Karanlık, Gürkan Karanlık, Sadin Özdemir, Gülşah Tollu, Ali Erdoğmuş
In the current study, we synthesized and characterized new BODIPY derivatives (1-4) having pyridine or thienyl-pyridine substituents at meso- position and 4-dibenzothienyl or benzo[b]thien-2-yl moieties at 2-,6- positions. We investigated fluorescence properties and the ability to form singlet oxygen. In addition, various biological activities of BODIPYs such as DPPH scavenging, DNA binding/cleavage ability, cell viability inhibition, antimicrobial activity, antimicrobial photodynamic therapy (aPDT) and biofilm inhibition properties were performed...
June 14, 2023: Photochemistry and Photobiology
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