Antiradical capacity assay for hydrophobic substances using hemin ‐catalyzed luminol chemiluminescence in cationic micelles
We describe here an antiradical capacity assay, based on luminol chemiluminescence, in cationic micellar medium, allowing the capacity determination of hydrophobic compounds. The an tiradical capacity of antioxidants is determined using the Trolox standard by the measurement of the light emission inhibition area caused by the addition of different antiradical concentrations. The obtained results are compared to the values determined using the scavenging of stable free radicals be the substances and shown to be similar for compounds like uric acid, rutin, and quercetin. However, for vitamin E, the luminol assay results in a...
Source: Photochemistry and Photobiology - February 24, 2024 Category: Science Authors: Cerize S. Santos,
Marcos P. O. Lemos,
Larissa M. Betschart,
Wilhelm J. Baader Tags: RESEARCH ARTICLE Source Type: research
Fluorescent styrenes for mitochondrial imaging and viscosity sensing
In this study, we designed fluorophores incorporating pyridinium and pentafluorophenyl pendants and examined their impact on sub-cellular localization. Remarkably, the fluorophores exhibited a notable propensity for the mitochondrial membrane. Furthermore, these fluorophores revealed dual functionality by facilitating the detection of viscosity changes within the sub-cellular environment and serving as heavy-atom-free photosensitizers. With easy chemical tunability, wash-free imaging, and a favorable signal-to-noise ratio, these fluorophores are valuable tools for imaging mitochondria and investigating their cellular proce...
Source: Photochemistry and Photobiology - February 23, 2024 Category: Science Authors: Deepmala Singh,
Mohini Ghorpade,
Ramprasad Regar,
Mayeul Collot,
Virupakshi Soppina,
Sriram Kanvah Tags: SPECIAL ISSUE RESEARCH ARTICLE Source Type: research
Reconciling TD ‐DFT and CASPT2 electronic structure methods for describing the photophysics of DNA
Hybrid quantum mechanics/molecular mechanics (QM/MM) molecular dynamics simulations on aqueous solvated uridine show that TD-DFT and CASPT2 reference methods predict very similar topologies of the potential energy surface of the lowestππ* excited state. The discrepant behavior, reported in previous publications, between the two methods in describing DNA in polar environments is addressable to the different relative energetics of theππ* andn π* states. We demonstrate that by adopting an appropriate scheme for modeling the environment, the considerably cheaper TD-DFT method could be positioned as the standout protocol t...
Source: Photochemistry and Photobiology - February 15, 2024 Category: Science Authors: Vishal Kumar Jaiswal,
Mario Taddei,
Daniel R. Nascimento,
Marco Garavelli,
Irene Conti,
Artur Nenov Tags: SPECIAL ISSUE Source Type: research
Blue light impairs the repair of UVB ‐induced pyrimidine dimers in a human skin model
Exposure of reconstructed human epidermis with blue light decreases the rate of repair of pyrimidine dimers induced in DNA by a subsequent UVB irradiation. This deleterious effect is prevented by application of a sunscreen exhibiting blue light photoprotection. AbstractIn recent years, interest is growing in the biological cutaneous effects of high-energy visible light (400 –450 nm). In the present study, we explored the impact of blue light (BL) on the repair of pyrimidine dimers, the major class of premutagenic DNA damage induced by exposure to sunlight. We unambiguously demonstrate that the exposure of in vitro rec...
Source: Photochemistry and Photobiology - February 13, 2024 Category: Science Authors: Thierry Douki,
Daniel Bacqueville,
Carine Jacques,
Camille Geni ès,
Nicolas Roullet,
Sandrine Bessou‐Touya,
Hélène Duplan Tags: RESEARCH ARTICLE Source Type: research
Associations between sun exposure, skin pH, and epidermal permeability in pregnancy: A longitudinal observational study
We identified an association between increased sun exposure and increased skin permeability at 18 –24 weeks' gestation (β = 0.85,p = 0.01) in pregnancy. Lower transepidermal water loss (decreased skin permeability) and higher skin pH readings were observed at 28–30 weeks' gestation compared to 18–24 weeks' and 36–38 weeks' gestation. AbstractLittle is known about how sun exposure may affect the maternal skin barrier during pregnancy when many hormonal and physiological changes occur. In this longitudinal observational study, 50 pregnant women were recruited at 18 –24 weeks' gestation, 25 in sum...
Source: Photochemistry and Photobiology - February 10, 2024 Category: Science Authors: Rachel Stevens,
Shelley Gorman,
Diana Arabiat,
Claus T. Christophersen,
Debra J. Palmer Tags: RESEARCH ARTICLE Source Type: research
Protective effect of isoquercitrin on UVB ‐induced injury in HaCaT cells and mice skin through anti‐inflammatory, antioxidant, and regulation of MAPK and JAK2‐STAT3 pathways
In conclusion, isoquercitrin pretreatment protected mice skin from UVB irradiation-induced injury effectively, and the underlying mechanism may involve MAPK and JAK2-STAT3 signaling pathways. (Source: Photochemistry and Photobiology)
Source: Photochemistry and Photobiology - February 10, 2024 Category: Science Authors: Yingyan Li,
Yunge Ma,
Yike Yao,
Guohua Ru,
Chong Lan,
Liyan Li,
Tao Huang Tags: RESEARCH ARTICLE Source Type: research
Transcriptome analysis in mouse skin after exposure to ultraviolet radiation from a canopy sunbed
Exposure to ultraviolet radiation (UV-R) emitting from a tanning equipment heightens skin cancer risk through molecular changes, with uncertain genomic impact. Using C57BL/6N mice, we explored dose- and time-dependent gene expression changes in their skin following erythemally weighted UV-R doses from a sunbed. The highest differentially expressed gene count occurred at 6 and 48 h post-exposure in the two highest dose groups, with the highest UV-R dose consistently perturbing genes related to skin barrier homeostasis. UV-R activated pathways involving inflammation, oxidative stress, repair, skin remodeling, and innate i...
Source: Photochemistry and Photobiology - February 6, 2024 Category: Science Authors: Sami S. Qutob,
Samantha P. M. Roesch,
Sandy Smiley,
Pascale Bellier,
Andrew Williams,
Kate B. Cook,
Matthew J. Meier,
Andrea Rowan ‐Carroll,
Carole L. Yauk,
James P. McNamee Tags: RESEARCH ARTICLE Source Type: research
Interactions of drosophila cryptochrome
In this study, we investigate the intricate regulatory mechanisms underlying the circadian clock inDrosophila, focusing on the light-induced conformational changes in the cryptochrome (DmCry). Upon light exposure, DmCry undergoes conformational changes that prompt its binding to Timeless and Jetlag proteins, initiating a cascade crucial for the starting of a new circadian cycle. DmCry is subsequently degraded, contributing to the desensitization of the resetting mechanism. The transient and short-lived nature of DmCry protein –protein interactions (PPIs), leading to DmCry degradation within an hour of light exposure, pre...
Source: Photochemistry and Photobiology - February 5, 2024 Category: Science Authors: Gozde Ozcelik,
Mehmet Serdar Koca,
Buket Sunbul,
Fatma Yilmaz ‐Atay,
Feride Demirhan,
Busra Tiryaki,
Kevser Cilenk,
Saba Selvi,
Nuri Ozturk Tags: RESEARCH ARTICLE Source Type: research
Excited state properties of 5 ‐fluoro‐4‐thiouridine derivative†
The excited state properties of 2 ′,3′,5′-tri-O-acetyl-5-fluoro-4-thiouridine in acetonitrile have been intensively investigated. The intrinsic triplet lifetime and the formation quantum yields of the excited triplet state and the singlet molecular oxygen were successfully determined. The fraction of triplet ta5F4TUrd quenched by dissolved oxygen which gives rise to the1O2* formation was the largest among the thionucleobases and the thionucleosides reported so far. AbstractThe excited state properties of thionated 5-fluorouridine (2 ′,3′,5′-tri-O-acetyl-5-fluoro-4-thiouridine; ta5F4TUrd), synthesized with Lawes...
Source: Photochemistry and Photobiology - February 5, 2024 Category: Science Authors: Rin Sato,
Yoshino Yamada,
Wataru Kashihara,
Tatsuya Nishihara,
Kazuhito Tanabe,
Yao ‐Zhong Xu,
Tadashi Suzuki Tags: SPECIAL ISSUE RESEARCH ARTICLE Source Type: research
Treatment of nonmelanoma skin cancer with pro ‐differentiation agents and photodynamic therapy: Preclinical and clinical studies (Review)
Photodynamic therapy (PDT) is now popular for treating nonmelanoma skin cancer (NMSC), but can be ineffective for larger skin tumors, mainly due to inadequate production of PpIX. Work over the past two decades has shown that differentiation-promoting agents, including methotrexate, 5-fluorouracil and vitamin D can be combined with ALA-PDT as neoadjuvants to promote tumor-specific accumulation of PpIX, enhance tumor-selective cell death, and improve therapeutic outcome. In this review, we provide a historical perspective of how the combinations of differentiation-promoting agents with PDT (cPDT) evolved, including initial d...
Source: Photochemistry and Photobiology - February 5, 2024 Category: Science Authors: Sanjay Anand,
Tayyaba Hasan,
Edward V. Maytin Tags: SPECIAL ISSUE INVITED REVIEW Source Type: research
Modulation of excited state intramolecular proton transfer and intramolecular charge transfer pathways of symmetrical azines through micellar medium
This study attempts to access the photophysical properties of the dual emitting azine based probe diethylamino salicylidene azine dimer (DEASAD) in micellar media. DEASAD showed dual charge transfer emission due to the presence of open enol (480 nm) and closed enol (510 nm) forms in polar protic solvents. Upon increasing the concentration of ionic surfactants, there is a significant increase in the emission intensity of both the enol forms of DEASAD until premicellar concentration. After micellization, occurrence of a new anomalous ket o form emission through excited state intramolecular proton transfer (ESIPT) was ob...
Source: Photochemistry and Photobiology - February 2, 2024 Category: Science Authors: Ramalingam Suhasini,
Ulagammal Venkatasubramanian,
Viruthachalam Thiagarajan Tags: SPECIAL ISSUE RESEARCH ARTICLE Source Type: research
Evidence for the involvement of keratinocyte ‐derived microvesicle particles in the photosensitivity associated with xeroderma pigmentosum type A deficiency
Hypothetical model by which UVR generates PAFR agonists via ROS which then result in skin inflammation. In this model, ROS generated by UVB result in MVP release via PAFR. XPA deficiency results in increased ROS and augmented responses. This process can be blocked by antioxidants, PAFR inhibitors and aSMase inhibitors. AbstractPhotosensitivity can be due to numerous causes. The photosensitivity associated with deficiency of xeroderma pigmentosum type A (XPA) has been previously shown to be associated with excess levels of the lipid mediator platelet-activating factor (PAF) generated by the keratinocyte. As PAF has been rep...
Source: Photochemistry and Photobiology - January 30, 2024 Category: Science Authors: Lea Christian,
Pranali Manjrekar,
Karen M. Henkels,
Christine M. Rapp,
Risha Annamraju,
Rushabh P. Lohade,
Shikshita Singh,
M. Alexandra Carpenter,
Saman Khan,
Michael G. Kemp,
Yanfang Chen,
Ravi P. Sahu,
Jeffrey B. Travers Tags: RESEARCH ARTICLE Source Type: research
Far ‐red active unsymmetrical squaraine dyes containing N‐arylated indoline donors for dye sensitized solar cells*
Dye-sensitized solar cell (DSSC) device efficiency of 3% (Jsc 5.72 mA cm−2,Voc 662 mV and ff 79%) has been achieved for an unsymmetrical squaraine dye,SQA5 with iodolyte electrolyte and the incident photon to current efficiency (IPCE) profile indicates the contribution of aggregated structures for the photocurrent generation. AbstractSquaraine dyes possess sharp far-red active transition with high extinction coefficient and form aggregates on TiO2 surface. Aggregation of dyes on TiO2 has been considered as a detrimental factor for DSSC device performance, which can be controlled by appending alkyl groups to the d...
Source: Photochemistry and Photobiology - January 29, 2024 Category: Science Authors: Avinash P. Jadhav,
Ambarish Kumar Singh,
Rinu Pandya,
Kumar Vanka,
Kothandam Krishnamoorthy,
Nithyanandhan Jayaraj Tags: SPECIAL ISSUE RESEARCH ARTICLE Source Type: research
Photophobotaxis in the filamentous cyanobacterium Phormidium lacuna: Mechanisms and implications for photosynthesis ‐based light direction sensing
How do filaments ofPhormidium lacuna find the lighted area? Each filament moves in random direction. If a filament crosses the light –dark border, it returns and stays in the light. AbstractCyanobacteriumPhormidium lacuna filaments move from dark to illuminated areas by twitching motility. Time-lapse recordings demonstrated that this photophobotaxis response was based on random movements with movement reversion at the light –dark border. The filaments in the illuminated area form a biofilm attached to the surface. The wild-type and thepixJ andcphA mutants were investigated for photophobotaxis at diverse wavelengths and...
Source: Photochemistry and Photobiology - January 26, 2024 Category: Science Authors: Elina Schwabenland,
Carolina Janine Jelen,
Nora Weber,
Tilman Lamparter Tags: RESEARCH ARTICLE Source Type: research
Biocidal polymer derived near white light ‐emitting polymeric carbon particles for antibacterial and bioimaging applications*
As a result of mixed sizes, doping, and surface effects, carbon dots (CD) exhibit an excitation-dependent photoluminescence, restricting them to specific applications. The present work created white light-emitting polymeric carbon particles (PCP) from a biocidal polymer and solvothermal synthesis, which were not only antibacterial but also showed greater biocompatibility and excitation independence. Electrospun nanofibers generated from composite polymers of PCP and PMMA were then used to fabricate antibacterial and bioimaging surfaces. AbstractA growing antimicrobial crisis has increased demand for antimicrobial materials...
Source: Photochemistry and Photobiology - January 24, 2024 Category: Science Authors: Shaifali Sartaliya,
Raina Sharma,
Anjana Sharma,
Vianni Chopra,
K. M. Neethu,
Arun Kumar Solanki,
Deepa Ghosh,
Govindasamy Jayamurugan Tags: SPECIAL ISSUE RESEARCH ARTICLE Source Type: research
