Photochemistry and Photobiology

Cover image for Vol. 90 Issue 2

Early View (Online Version of Record published before inclusion in an issue)

Edited By: Jean Cadet

Impact Factor: 2.287

ISI Journal Citation Reports © Ranking: 2012: 40/72 (Biophysics); 188/290 (Biochemistry & Molecular Biology)

Online ISSN: 1751-1097

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  1. 1 - 60
  1. Research Articles

    1. Excited State Photoreaction between the Indole Side Chain of Tryptophan and Halocompounds Generates New Fluorophores and Unique Modifications

      Carol L. Ladner, Khai Tran, Mary Le, Raymond J. Turner and Robert A. Edwards

      Article first published online: 17 APR 2014 | DOI: 10.1111/php.12279

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      Several fluorophores were produced by photoreactions between the amino acid tryptophan and halocompounds. The reaction with trihalocompounds in aqueous solution yielded products with carbonyl groups conjugated to the aromatic system at the 4 and 6 positions of the indole fluorophore and led to emission near 500 nm. This photoreaction also proceeded with monohalocompounds, but resulted in additions to the indole fluorophore without enlarging the conjugated systems so that the fluorescence properties of the indole in tryptophan did not change significantly.

    2. Observation of Magnetic Field Effects on Transient Fluorescence Spectra of Cryptochrome 1 From Homing Pigeons

      Xian-li Du, Jing Wang, Wei-song Pan, Qi-jun Liu, Xiao-jie Wang and Wen-jian Wu

      Article first published online: 17 APR 2014 | DOI: 10.1111/php.12276

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      Cryptochrome is suggested to be the most probable candidate magnetoreceptor in bird magnetoreception. Two members of cryptochrome/photolyase family have been found to be sensitive to the magnetic field and the magnetic sensitivity was proposed to be the general feature of this protein family. In this study, we constructed a magnetic field by Helmholtz coils and tested the magnetic field effects on the transient fluorescence of cryptochrome from homing pigeons at room temperature. Our results showed that, comparing to other flavin controls, the transient fluorescence of clCRY1 protein is sensitive to microtesla level magnetic field.

    3. Chlorin e6 Derivative Radachlorin Mainly Accumulates in Mitochondria, Lysosome and Endoplasmic Reticulum and Shows High Affinity toward Tumors in Nude Mice in Photodynamic Therapy

      Raktim Biswas, Jeong Hwan Moon and Jin-Chul Ahn

      Article first published online: 17 APR 2014 | DOI: 10.1111/php.12273

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      Cellular uptake and tumor affinity of chlorin e6 photosensitizer, radachlorin were studied in anaplastic thyroid cancer cells and xenograft nude mice model. Results showed radachlorin mainly accumulated in mitochondria and partially in lysosome and endoplasmic reticulum. It showed a higher accumulation in tumor site within 3–6 h and was further cleared from the tumor in next 24–48 h. Radachlorin also showed a higher efficacy in photodynamic therapy after 6 h of drug injection. Therefore, the knowledge of possible sites and time of photosensitizers accumulation in tumor cells may help in optimizing the efficacy of PDT.

    4. Two Methods for Retrieving UV Index for All Cloud Conditions from Sky Imager Products or Total SW Radiation Measurements

      Jordi Badosa, Josep Calbó, Richard Mckenzie, Ben Liley, Josep-Abel González, Bruce Forgan and Charles N. Long

      Article first published online: 17 APR 2014 | DOI: 10.1111/php.12272

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      Cloud effects on UV Index (UVI) and total solar radiation (TR) are assessed. The role of cloud cover and sunny conditions (from sky images) and of solar zenith angle is investigated. The analyses are undertaken for a southern-hemisphere mid-latitude site where a 10-years dataset is available. It is confirmed that clouds affect TR more than UVI, both in reducing and enhancing the cloud-free radiation. From the analyses, two methods to estimate UVI are developed: (1) from sky imaging cloud cover and sunny conditions, and (2) from TR measurements. Methods' estimations are compared with measurements.

    5. Topical Photodynamic Therapy Using Different Porphyrin Precursors Leads to Differences in Vascular Photosensitization and Vascular Damage in Normal Mouse Skin

      Tom A. Middelburg, Hannah C. de Vijlder, Henriette S. de Bruijn, Angélique van der Ploeg-van den Heuvel, H. A. Martino Neumann, Ellen R. M. de Haas and Dominic J. Robinson

      Article first published online: 7 APR 2014 | DOI: 10.1111/php.12271

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      The ability of the vasculature to synthesize PpIX and be damaged by PDT was compared between HAL, ALA and MAL in mouse skin using confocal microscopy and fluorescent CD31 and CD144 antibodies. Colocalization of CD31 and PpIX (left images) was calculated to measure endothelial PpIX synthesis. Vascular damage was scored as loss of normal CD144 staining (right images). Both PpIX synthesis and vascular damage were highest for HAL, then ALA, then MAL. This illustrates that superficial blood vessels synthesize biologically relevant amounts of PpIX. Vascular responses can limit oxygen supply during or after PDT and are expected to influence outcome.

    6. Enhanced Efficacy of Photodynamic Therapy via a Sequential Targeting Protocol

      David Kessel and John J. Reiners Jr

      Article first published online: 1 APR 2014 | DOI: 10.1111/php.12270

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      Testing for iron translocation using fluorescent probes: red = RhoNox-1 (Ferrous iron); green = LysoTracker Green (A) or MitoTracker Green (B–D). Iron is initially localized in lysosomes (A), not mitochondria (B). Treatment with Bafilomycin results in substantial translocalization to mitochondria (C), whereas a low level of lysosomal photodamage does not (D). Either effect can markedly promote the efficacy of subsequent mitochondrial photodamage but via different mechanisms.

    7. Tyrosine 263 in Cyanobacterial Phytochrome Cph1 Optimizes Photochemistry at the prelumi-R→lumi-R Step

      Vitaly Sineshchekov, Joel Mailliet, Georgios Psakis, Kathleen Feilke, Jakub Kopycki, Mathias Zeidler, Lars-Oliver Essen and Jon Hughes

      Article first published online: 28 MAR 2014 | DOI: 10.1111/php.12263

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      Y263 in Cph1 is perfectly conserved among phytochromes, even though mutations at that site seemed to be innocuous. Here we show that, on the contrary, tyrosine is important in optimizing photochemistry toward lumi-R at the of S0/S1 conical intersection (prelumi-R). A possible structure of the prelumi-R phantom state is shown here.

    8. Phosphorylation of Histone H2AX Generated by Linear Alkylbenzene Sulfonates and its Suppression by UVB Exposure

      Toru Kubota, Tatsushi Toyooka, Xiaoxu Zhao and Yuko Ibuki

      Article first published online: 26 MAR 2014 | DOI: 10.1111/php.12268

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      Linear alkylbenzene sulfonates (LAS), general anion surfactants, generated DNA double-strand breaks (DSBs) with phosphorylation of histone H2AX (γ-H2AX). The ability to generate γ-H2AX was markedly reduced in LAS exposed to UVB. HPLC analysis revealed that UVB evenly decreased all peaks of LAS, without migration of peaks to other retention times, which indicated that UVB may degrade the benzene ring of LAS, but did not shorten the alkyl chains. UVB is an important environmental factor in the degradation of LAS exhibiting the ability to induce DSBs, the most serious type of DNA damage.

    9. Membrane Damage Efficiency of Phenothiazinium Photosensitizers

      Isabel O. L. Bacellar, Christiane Pavani, Elisa M. Sales, Rosangela Itri, Mark Wainwright and Mauricio S. Baptista

      Article first published online: 26 MAR 2014 | DOI: 10.1111/php.12264

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      Structure–activity relationships were investigated for a series of phenothiazinium photosensitizers (methylene blue, toluidine blue O, 1,9-dimethyl methylene blue and DO15). We compared the ability of these compounds to damage membranes by quantifying the efficiency of liposome permeabilization, which was correlated with singlet-oxygen generation within the membranes, membrane/solution partition and tendency of aggregation of the photosensitizers. We concluded that membrane-based protocols can provide a better understanding on the photodynamic efficiency of the photosensitizer.

    10. The Effect of Photodynamic Action on Leakage of Ions Through Liposomal Membranes that Contain Oxidatively Modified Lipids

      Shany Ytzhak and Benjamin Ehrenberg

      Article first published online: 25 MAR 2014 | DOI: 10.1111/php.12266

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      We measured the integrity of the liposomal membrane when it includes oxidatively modified lipids and when it is exposed to photodynamic action by photosensitization with hematoporphyrin. We demonstrate that the photodynamic process, in which unsaturated lipids of natural lecithin are damaged, is not causing the lipid bilayer to leak, but it strongly accelerates the leakage of ions if a very small fraction of the natural lipids are replaced by the modified lipids.

    11. Quantification of Ocular Biologically Effective UV Exposure for Different Rotation Angle Ranges Based on Data from a Manikin

      Liwen Hu, Fang Wang, Nan-Ning Ou-Yang, Na Gao, Qian Gao, Tiantian Ge, Yanyan Gao, Guangcong Liu, Yang Zheng and Yang Liu

      Article first published online: 24 MAR 2014 | DOI: 10.1111/php.12267

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      To improve the understanding of solar UV and the biologically effective UV exposure at eye (UVBE), this study monitored the ocular UV exposure at different rotation angles using a rotating manikin in clear skies during July 2010 in Sanya, China. The rotation angle ranges were the ranges of the eye facing the sun or facing away from the sun; for example, the 60° rotation angle range facing the sun was the rotation angle of 330° to 30°, and the 180° rotation angle range facing away from the sun included the rotation angles between 90° and 270°.

    12. Measuring Exposure to Solar Ultraviolet Radiation Using a Dosimetric Technique: Understanding Participant Compliance Issues

      Jiandong Sun, Robyn M. Lucas, Simone L. Harrison, Ingrid van der Mei, David C. Whiteman, Rebecca Mason, Madeleine Nowak, Alison M. Brodie and Michael G. Kimlin

      Article first published online: 24 MAR 2014 | DOI: 10.1111/php.12265

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      Among 10 020 polysulphone UV dosimeters distributed in the AusD Study, the majority (89%) were returned with no reported issues, but 3% were not returned or used and 8% were returned with self-reported usage errors such as “missing some time,” “covered by clothing,” or “dosimeter got wet” that may potentially compromise the measurement quality. We found these noncompliance issues were more frequently reported on the first day of measurement; weekend days or rainy days; and among females; younger people; more educated participants or those with predominantly outdoor occupations. These factors should be considered when designing future UV dosimetry studies.

    13. Photophysics of a Coumarin in Different Solvents: Use of Different Solvatochromic Models

      Banibrata Maity, Aninda Chatterjee and Debabrata Seth

      Article first published online: 18 MAR 2014 | DOI: 10.1111/php.12258

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      This study demonstrated the photophysics of 7-(diethylamino)coumarin-3-carboxylic acid N-succinimidyl ester (7-DCCAE) in the presence of different neat solvents. Different empirical solvatochromic models were used to analyze the solvatochromic shift of 7-DCCAE in different solvents.

  2. Original Articles

    1. Dimerization of Resveratrol Induced by Red Light and Its Synergistic Analgesic Effects with Cobra Neurotoxin

      Yong Ye, Fei Fang and Yue Li

      Article first published online: 15 MAR 2014 | DOI: 10.1111/php.12262

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      A new synthetic method is designed for resveratrol dimer, which is induced by the excitation of photosensitizer pheophorbide at red light of 630 nm, the mechanism is illustrated. The dimer interacts with cobra neurotoxin and forms a complex substance, which shows significant synergistic analgesic effects after combined administration to mice. The dimer has multiple targets, and its combination with cobra neurotoxin may make up for their deficiencies in analgesic effects suggesting good prospects in clinical use.

  3. Research Articles

    1. Measurement of Intracellular Oxygen Concentration During Photodynamic Therapy in vitro

      Mark A. Weston and Michael S. Patterson

      Article first published online: 14 MAR 2014 | DOI: 10.1111/php.12256

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      A novel technique is described that measures the intracellular ground state oxygen concentration ([3O2]) during photodynamic therapy of cell monolayers and cell suspensions. The photosensitizer Pd(II) meso-tetra(4-carboxyphenyl)porphine (PdT790) is used to deplete the cells of 3O2 by photodynamic action while simultaneously monitoring the intracellular [3O2]. The intracellular [3O2] is calculated using the steady-state phosphorescence signal emitted by PdT790 during treatment. It was found that cells remain well oxygenated during PDT of cell suspensions, while for monolayer treatments intracellular [3O2] is rapidly reduced.

    2. Autonomous Portable Solar Ultraviolet Spectroradiometer (APSUS) – a New CCD Spectrometer System for Localized, Real-Time Solar Ultraviolet (280–400 nm) Radiation Measurement

      Rebecca Hooke, Andy Pearson and John O'Hagan

      Article first published online: 10 MAR 2014 | DOI: 10.1111/php.12251

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      A new prototype portable CCD (charge-coupled device) spectrometer-based instrument called APSUS (Autonomous Portable Solar Ultraviolet Spectroradiometer) has been developed which monitors spectral UV (280–400 nm) radiation levels at the earth's surface. The APSUS system enables the UV index to be calculated and disseminated to the public in real time. The APSUS unit incorporates an Ocean Optics QE65000 spectrometer contained within a robust environmental housing. It can gather reliable data from approximately April to October inclusive (depending on ambient temperature) in the UK. In this study the new APSUS unit and APSUS system are presented.

    3. Bistable Retinal Schiff Base Photodynamics of Histidine Kinase Rhodopsin HKR1 from Chlamydomonas reinhardtii

      Alfons Penzkofer, Meike Luck, Tilo Mathes and Peter Hegemann

      Article first published online: 8 MAR 2014 | DOI: 10.1111/php.12246

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      In HKR1 two thermally stable retinal Schiff base (RSB) forms RetA and RetB exist. RetA is deprotonated 13-cis, 15-anti RSB absorbing in the UV. RetB is protonated all-trans 15-anti and 15-syn RSB absorbing blue light. RetB is blue-light convertible to RetA with quantum efficiency of 0.4. RetA is UVA light convertible to RetB with quantum efficiency of 0.1.

    4. Photoexcited States of UV Absorbers, Benzophenone Derivatives

      Ryo Kumasaka, Azusa Kikuchi and Mikio Yagi

      Article first published online: 7 MAR 2014 | DOI: 10.1111/php.12257

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      The energy levels and lifetimes of the lowest excited triplet states of benzophenone (BP) derivatives, BP-2, BP-3, BP-6, BP-7 and BP-12, used as organic UV absorbers in cosmetic sunscreens were determined in rigid solutions at 77 K. The time-resolved near-IR emission spectrum of singlet oxygen generated by photosensitization with BP-7 was observed in acetonitrile at room temperature. BP-2, BP-3, BP-6 and BP-12 show photoinduced phosphorescence enhancement in ethanol at 77 K.

    5. Bystander Effect Induced by UVC Radiation in Chinese hamster V79 cells

      Shengwen Wu, Cuihong Jin, Xiaobo Lu, Jinghua Yang, Qiufang Liu, Ming Qi, Shuai Lu, Lifeng Zhang and Yuan Cai

      Article first published online: 5 MAR 2014 | DOI: 10.1111/php.12255

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      This study showed that UVC radiation induced some damage in irradiated V79 cells, which might initiate apoptosis progress when damage couldn't be repaired. The UVC-irradiated apoptotic cells released gradually some soluble factors into irradiated conditioned medium (ICMs) which finally induced bystander effect in unirradiated V79 cells.

    6. Efficacy of Low-Dose Ultraviolet A-1 Phototherapy for Parapsoriasis/Early-Stage Mycosis Fungoides

      Kenan Aydogan, Serkan Yazici, Saduman Balaban Adim, Isil Tilki Gunay, Ferah Budak, Hayriye Saricaoglu, Sukran Tunali and Emel Bulbul Baskan

      Article first published online: 5 MAR 2014 | DOI: 10.1111/php.12253

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      Skin-directed therapies are currently available treatment options for plaque type PP/early-stage MF with some limitations, and management of the diseases is still challenging. Ultraviolet A-1 (340–400 nm) phototherapy was first described in 1978 and it has became a valuable treatment for sclerotic and T-cell mediated diseases, more deeply penetrates than UVB. This study showed that Low-dose UVA-1 therapy seems to be a safe and effective alternative to other therapeutic options in patients with PP/early-stage MF who do not tolerate or respond to PUVA and UVB therapy, without systemic effect.

    7. The Number of Accumulated Photons and the Quality of Stimulated Emission Depletion Lifetime Images

      Aleem Syed, Michael D. Lesoine, Ujjal Bhattacharjee, Jacob W. Petrich and Emily A. Smith

      Article first published online: 3 MAR 2014 | DOI: 10.1111/php.12248

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      Photon counts in the peak channel of stimulated emission depletion fluorescence lifetime decay curves are increased by time binning without affecting the spatial resolution of the measurements. The fluorescence lifetime of Alexa Fluor 594 phalloidin bound to F-actin is probed in cultured cells at a spatial resolution 10-fold better compared to confocal imaging. Pixel-by-pixel fluorescence lifetime measurements and error analysis show that an average of 40 ± 30 counts in the peak channel with a signal-to-noise ratio of 20 is enough to calculate a reliable fluorescence lifetime from a single exponential fluorescence decay.

    8. Occupational UV Exposure of Environmental Agents in Valencia, Spain

      María-Antonia Serrano, Javier Cañada, Juan Carlos Moreno, Gonzalo Gurrea and Members of the Valencia Solar Radiation Research Group

      Article first published online: 26 FEB 2014 | DOI: 10.1111/php.12252

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      The aim of this paper is to measure UV exposure of environmental agents in their occupational schedules in summer in Valencia province (Spain) using VioSpor personal dosimeters attached to several parts of their bodies. Due to its geographical situation, Valencia receives large UVR doses throughout the year, and the work of environmental agents is directly related to the protection, care, and custody of natural, often in mountainous areas. Comparison with the occupational UV exposure limit showed that the agents received an erythemal UV dose in excess of occupational guidelines, indicating that protective measures against this risk are highly advisable.

    9. Antioxidative Activities of Algal Keto Carotenoids Acting as Antioxidative Protectants in the Chloroplast

      Michael Dambeck and Gerhard Sandmann

      Article first published online: 26 FEB 2014 | DOI: 10.1111/php.12249

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      Carotenoids and especially their keto derivatives are known for their antioxidative potential. Therefore the keto carotenoids peridinin, siphonaxanthin, fucoxanthin and astaxanthin mono fatty acid ester were isolated from different algae. They were assayed for their antioxidative properties as quenchers of singlet oxygen and oxo radicals and their potential was determined to protect against singlet oxygen- or radical-mediated peroxidation reactions.

    10. Hypericin as a Marker for Determination of Myocardial Viability in a Rat Model of Myocardial Infarction

      Cuihua Jiang, Yue Li, Xiao Jiang, Nan Yao, Meng Gao, Xueli Zhang, Junying Wang, Xiaoning Wang, Ziping Sun, Jian Zhang and Yicheng Ni

      Article first published online: 26 FEB 2014 | DOI: 10.1111/php.12247

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      The aim of this study was to investigate the necrosis avid agent hypericin as a potential indicator for determination of myocardial infarction. Animals were challenged with different doses of hypericin (0, 1, 2, and 5 mg kg−1) after an experimental myocardial infarction. Infarct-to-normal contrast ratio and relative infarct size were evaluated by fluorescence macroscopy in colocalization with triphenyltetrazoliumchloride and histomorphology. Results confirm that hypericin specifically labeled necrosis, and enhanced the imaging contrast between the infarcted and normal myocardium, suggesting its potential applications for the assessment of myocardial viability.

    11. Effects of white light-emitting diode (LED) light exposure with different Correlated Color Temperatures (CCTs) on human lens epithelial cells in culture

      Chen Xie, Xiuyi Li, Jianping Tong, Yangshun Gu and Ye Shen

      Article first published online: 25 FEB 2014 | DOI: 10.1111/php.12250

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      Oxidative stress on the lens epithelial cells (hLECs) is the most important factor in cataract formation. Cumulative light exposure from widely used light-emitting diodes (LEDs) may pose a potential oxidative threat to the lens epithelium, due to the high-energy blue light component in the white-light emission from diodes. LED light having a CCT of 7378 K caused overproduction of intracellular ROS and severe cellular damage, which indicate that white LEDs with a high CCT could cause significant photobiological damage to hLECs and detailed industrial standards for this new artificial light source should be determined for the sake of ocular safety.

  4. Rapid Communications

    1. The Effect of Loading Palladium on Zinc Oxide on the Photocatalytic Degradation of Methyl tert-Butyl Ether (MTBE) in Water

      Zaki S. Seddigi, Saleh A. Ahmed, Shahid P. Ansari, Naeema H. Yarkandi, Ekram Danish, Abdullah Abu Alkibash, Mohammed D. Y. Oteef and Shakeel Ahmed

      Article first published online: 23 FEB 2014 | DOI: 10.1111/php.12242

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      Approximately complete removal of MTBE was achieved within 5 h by using ZnO particles doped with 1% Pd. The efficient degradation of MTBE is due to the higher concentration of the hydroxyl radicals and to the presence of Pd that controls the recombination of photogenerated electron hole pair.

  5. Research Articles

    1. Influences of Acid on Molecular Forms of Fluorescein and Photoinduced Electron Transfer in Fluorescein-Dispersing Sol–Gel Titania Films

      Hiromasa Nishikiori, Rudi Agus Setiawan, Kyohei Miyashita, Katsuya Teshima and Tsuneo Fujii

      Article first published online: 23 FEB 2014 | DOI: 10.1111/php.12254

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      Fluorescein-dispersing titania gel films were prepared by the acid-catalyzed sol–gel reaction using a titanium alkoxide solution containing fluorescein. The titanium species were coordinated to the carboxylate and phenolate-like groups of the fluorescein species. The quantum efficiencies of the fluorescence quenching and photoelectric conversion were higher upon excitation of the dianion species interacting with the titania, i.e. the dye–titania complex. Using nitric acid as the catalyst, the titania surface bonded to the fluorescein instead of the adsorbed nitrate ion during the steam treatment. The complex formation played an important role in the electron injection from the dye to the titania.

    2. Quantitative and in situ Detection of Oxidatively Generated DNA Damage 8,5′-Cyclo-2′-Deoxyadenosine Using an Immunoassay with a Novel Monoclonal Antibody

      Takaaki Iwamoto, Philip J. Brooks, Tomohisa Nishiwaki, Kazuki Nishimura, Nobuhiko Kobayashi, Shigeki Sugiura and Toshio Mori

      Article first published online: 23 FEB 2014 | DOI: 10.1111/php.12239

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      Xeroderma pigmentosum (XP) is a genetic disorder associated with defects in nucleotide excision repair, which eliminates a wide variety of helix-distorting DNA damage including sunlight-induced pyrimidine dimers. In addition to skin disease, approximately 30% of XP patients develop progressive neurological disease, which has been hypothesized to be associated with the accumulation of oxidatively generated DNA damage called purine cyclonucleosides. In this study, we generated a novel monoclonal antibody (CdA-1) specific for purine cyclonucleosides in DNA that recognizes 8,5′-cyclo-2′-deoxyadenosine (cyclo-dA). An immunofluorescent analysis using CdA-1 enabled the visualization of cyclo-dA (green dots) in human osteosarcoma cells, which had been transfected with oligonucleotides containing 5′S-cyclo-dA.

  6. Research Notes

    1. Preparation and Characterization of Uniform Near IR Polystyrene Nanoparticles

      Michal Pellach and Shlomo Margel

      Article first published online: 20 FEB 2014 | DOI: 10.1111/php.12244

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      In vivo fluorescence imaging requires the use of near IR fluorescent imaging agents, to avoid the absorbance and autofluorescence of endogenous tissues that occur at visible wavelengths. Near IR dye was encapsulated into polystyrene nanoparticles via a swelling process. The dye encapsulation process was performed for a series of differently sized nanoparticles, without affecting the relatively uniform size distribution of each size. The method used was found to be appropriate for nanoparticles averaging approximately 20–100 nm in size. The resulting nanoparticles were highly fluorescent and highly photostable, and with appropriate surface modification, have potential for biological and in vivo imaging applications.

  7. Research Articles

    1. Synthesis and Characterization of Near-Infrared Absorbing Water Soluble Squaraines and Study of their Photodynamic Effects in DLA Live Cells

      Kulathinte M. Shafeekh, Mohanannair S. Soumya, Moochikkadavath A. Rahim, Annie Abraham and Suresh Das

      Article first published online: 17 FEB 2014 | DOI: 10.1111/php.12236

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      Synthesis, photophysical properties and photodynamic effects in DLA live cells of three water soluble squaraine dyes, SQDI, SQMI and ASQI, are presented. On photoirradiation, both the SQDI and SQMI generate singlet oxygen where both the dyes undergoing oxidation reactions with the singlet oxygen generated, whereas ASQI was stable and did not react with the singlet oxygen. In vitro cytotoxicity studies of these dyes in DLA cells were performed using Trypan blue dye exclusion method and intracellular generation of ROS was confirmed using dichlorofluorescein assay after the in vitro PDT.

    2. Analysis of Photoexcitation Energy Dependence in the Photoluminescence of Firefly Luciferin

      Miyabi Hiyama, Hidefumi Akiyama, Toshimitsu Mochizuki, Kenta Yamada and Nobuaki Koga

      Article first published online: 15 FEB 2014 | DOI: 10.1111/php.12243

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      By considering protonation/deprotonation, the whole pathways for photoluminescence of firefly luciferin in aqueous solutions of different pH values with different photoexcitation energies were theoretically investigated.

    3. Photodecomposition of Chloroform Catalyzed by Unmodified MCM-41 Mesoporous Silica

      Laura A. Peña, Alissa M. Chan, Larissa R. Cohen, Karen Hou, Brent M. Harvey and Patrick E. Hoggard

      Article first published online: 15 FEB 2014 | DOI: 10.1111/php.12245

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      Unmodified MCM-41 silica catalyzes the photodecomposition of chloroform under near-UV irradiation. It is proposed that decomposition is initiated through hydrogen abstraction from chloroform at a photoactive SiO2 defect site.

    4. Early Diagnosis of Colorectal Cancer in Rats With DMH Induced Carcinogenesis by Means of Urine Autofluorescence Analysis

      Zuzana Šteffeková, Anna Birková, Alojz Bomba and Mária Mareková

      Article first published online: 15 FEB 2014 | DOI: 10.1111/php.12240

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      Cancer is one of the most highlighted topics of current research. Early detection of this disease allows more effective therapy, hence higher chance of cure. Application of fluorescence spectral techniques into oncological diagnostic is one of the potential alternatives. Chemically induced carcinogenesis in rats is widely used model for exploration of various aspects of colorectal cancer. This study shows value of discriminate analysis of urine fluorescent fingerprint between healthy control group of rats and those with dimethylhydrazine induced early lesions of colorectal cancer. Using fluorescence spectroscopy significant difference (P < 0.05) between both of group was achieved.

  8. Research Notes

    1. Home Lighting Before Usual Bedtime Impacts Circadian Timing: A Field Study

      Helen J. Burgess and Thomas A. Molina

      Article first published online: 7 FEB 2014 | DOI: 10.1111/php.12241

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      After sunset, we often turn on our lights at home. In this field study, we found that maximizing evening light at home in the 4 h before usual bedtime, delayed the dim light melatonin rhythm by about 1 h, when compared to dim light in the evening. These results highlight that evening light at home can delay central circadian timing and contribute to circadian misalignment.

  9. Research Articles

    1. Photosensitive and Biomimetic Core–Shell Nanofibrous Scaffolds as Wound Dressing

      Guorui Jin, Molamma P Prabhakaran and Seeram Ramakrishna

      Article first published online: 4 FEB 2014 | DOI: 10.1111/php.12238

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      A photosensitive polymer, namely, poly (3-hexylthiophene) is encapsulated within the core–shell-structured Gel/PLLCL fibers by coaxial electrospinning. The proliferation of human dermal fibroblasts was significantly improved on the core–shell nanofibers under light stimulation compared to fibroblasts on the same scaffold under nonstimulated condition. Moreover, the stem cells on the photosensitive scaffolds under light stimulation were more likely to differentiate into epidermal lineages compared to cells without stimulation. Our results suggest that the photosensitive core–shell nanofibers can serve as a novel substrate to promote skin regeneration.

  10. Invited Reviews

    1. You have free access to this content
      Shade Provision for UV Minimization: A Review

      Alfio V. Parisi and David J. Turnbull

      Article first published online: 4 FEB 2014 | DOI: 10.1111/php.12237

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      Providing and using natural and built shade is an effective protection measure against harmful UV. This article describes the factors that must be addressed to ensure quality, effective, well-designed shade and recommends best practice approaches to improving the protection factor of shade structures. It identifies examples of interventions to increase shade availability and use, and examples of effective shade based on measured protection factors or measured reductions in UV exposures. Finally, this article considers examples of best practice for undertaking shade audits.

  11. Original Articles

    1. Practical Labeling Methodology for Choline-Derived Lipids and Applications in Live Cell Fluorescence Imaging

      Caishun Li, Jessie A. Key, Feng Jia, Arpan Dandapat, Soo Hur and Christopher W. Cairo

      Article first published online: 31 JAN 2014 | DOI: 10.1111/php.12234

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      Fluorescent probes can be used to investigate the structure and dynamics of the plasma membrane. Exogenous fluorescent lipid probes which integrate into the membrane are often used for this purpose. In this study, we investigate the utility of metabolic labeling of phosphocholine-derived lipids for introducing fluorescent probes. Using synthetic fluorophores that react with bioorthogonal metabolic labels, we labeled live cell membranes. We demonstrate that these labeled lipids can be used for a variety of applications including imaging, measurement of lipid dynamics (lateral diffusion) and chemical adhesion of the cells to reactive surfaces.

  12. Research Articles

    1. Biochemical Composition and Antioxidant Properties of Lavandula angustifolia Miller Essential Oil are Shielded by Propolis Against UV Radiations

      Gismondi Angelo, Canuti Lorena, Grispo Marta and Canini Antonella

      Article first published online: 28 JAN 2014 | DOI: 10.1111/php.12229

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      Propolis shields Lavandula angustifolia Miller essential oil from UV-induced photodegradation. Lavender biochemical components are strongly degraded by UV radiations and consequently their antioxidant properties, in in vitro assays and directly on B16F10 cells, are decreased. Propolis is proposed as highly efficient UV protective and antiradical additive for sunscreens, cosmetics and alimentary or pharmaceutical products containing plant extracts.

    2. Photophysical Properties of Metal Ion Functionalized NaY Zeolite

      Tian-Wei Duan and Bing Yan

      Article first published online: 28 JAN 2014 | DOI: 10.1111/php.12235

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      A series of luminescent ion exchanged zeolite are synthesized by introducing various ions into NaY zeolite. The produced materials can be divided into three types: metal exchanged zeolite, rare-earth exchanged NaY zeolite modified with Y3+ and rare-earth exchanged NaY zeolite modified with Zn2+.

    3. Characterization of the Triplet State of Tanshinone IIA and its Reactivity by Laser Flash Photolysis

      Kun Li, Qin Zhang, Mei Wang, Rongrong Zhu, Xiaoyu Sun, Xianzheng Wu and Shi-Long Wang

      Article first published online: 27 JAN 2014 | DOI: 10.1111/php.12220

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      Photosensitization by energy transfer from triplet state of photosensitizer to Tan IIA or direct photoexcitation of Tan IIA by 355 nm laser pulses lead to generation of triplet state of Tan IIA which can react with DMA and TBHQ and PGA via electron transfer in acetonitrile and experience self-quenching reaction via autooxidation in cyclohexane.

    4. Photodamage in a Mitochondrial Membrane Model Modulated by the Topology of Cationic and Anionic Meso-Tetrakis Porphyrin Free Bases

      Cintia Kawai, Juliana C. Araújo-Chaves, Taciana Magrini, Camila O. C. C. Sanches, Sandra M. S. Pinto, Herculano Martinho, Nasser Daghastanli and Iseli L. Nantes

      Article first published online: 23 JAN 2014 | DOI: 10.1111/php.12228

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      TMPyP binds to the liposome and generates singlet oxygen from molecular oxygen dissolved into bilayer. TPPS4 transfers electronic excitation to bulk molecular oxygen and generates singlet oxygen that travels through solution and attacks a distant lipid bilayer.

    5. Inactivation of Bacillus subtilis Spores Using Various Combinations of Ultraviolet Treatment with Addition of Hydrogen Peroxide

      Yiqing Zhang, Lingling Zhou, Yongji Zhang and Chaoqun Tan

      Article first published online: 21 JAN 2014 | DOI: 10.1111/php.12210

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      The facility used in the experiments was a collimated beam apparatus containing a low-pressure mercury lamp. Petri dishes (90 mm diameter) with 40 mL samples were exposed to the UV in the collimated beam apparatus and stirred gently by a magnetic stirring apparatus. The inactivation of Bacillus subtilis spores of various combinations of UV treatment and H2O2 addition were compared, including sequential (UV-H2O2, H2O2–UV) and simultaneous (UV/H2O2) processes.

    6. Novel Porphyrazine Derivatives show Promise for Photodynamic Therapy despite Restrictions in Hydrophilicity

      Tamarisk K. Horne and Marianne J. Cronjé

      Article first published online: 21 JAN 2014 | DOI: 10.1111/php.12231

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      Complexing of ligands to photosensitizers (Ps) can enhance solubility, cell-surface recognition and tissue specificity for applications in Photodynamic Therapy (PDT). Nine carbohydrate-functionalized porphyrazine (Pz-galactopyranose/methyl-ribose) derivatives with H2, Zn(II) or Ni(II) cores were analyzed for potential use in PDT.

      • Derivatives solubilized in DCM and tetrahydrofuran were cytotoxic; encapsulation in DCM-based PEG-DSPE5000-PBS was biologically suitable.
      • No correlation between core ion, carbohydrate type and peripheral position was revealed via absorption spectra analyses. Encapsulation efficiency (%EE): Zn(II) (60–92%) > H2 (5–34%) > Ni(II) (4–21%).
      • Phototoxicity of Zn(II)Pz derivatives showed highest efficiency following excitation in MCF-7 cells, and show promise as anticancer PDT agents.
  13. Research Notes

    1. Novel Photodynamic Effect of a Psoralen-Conjugated Oligonucleotide for the Discrimination of the Methylation of Cytosine in DNA

      Asako Yamayoshi, Yohei Matsuyama, Mikihiko Kushida, Akio Kobori and Akira Murakami

      Article first published online: 21 JAN 2014 | DOI: 10.1111/php.12232

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      We designed a psoralen-conjugated oligonucleotide (PS-oligo) for the discrimination of 5-methylcytosine (5-mC) in DNA. The cross-linking behavior of psoralen derivatives with pyrimidine bases, such as thymine, uracil and cytosine has been well discussed, but there are no reports which have examined whether cross-linking efficiency of psoralen with cytosine would be changed with or without C-5 methylation. We found that the cross-linking efficiency of PS-oligo with target-DNA containing 5-mC was greatly increased compared to the case of target-DNA without 5-mC, approximately seven-fold higher.

  14. Research Articles

    1. Effect of Light on Expression of Clock Genes in Xenopus laevis Melanophores

      Maria Nathália de Carvalho Magalhães Moraes, Maristela de Oliveira Poletini, Bruno Cesar Ribeiro Ramos, Leonardo Henrique Ribeiro Graciani de Lima and Ana Maria de Lauro Castrucci

      Article first published online: 18 JAN 2014 | DOI: 10.1111/php.12230

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      In light-sensitive cells, environmental light may be transduced through melanopsins (pigment excited by short wavelength) which, in turn, regulates the machinery of endogenous molecular clock through an increase in Per1 expression. In a nonmammalian vertebrate cell line (X. laevis melanophore), we demonstrated that a blue-light pulse increases Per1 and Per2 expression, and that Per1 gene expression oscillates in a circadian fashion under light–dark cycle. Thus, these cells are a promising model to investigate the biological mechanisms involved in photoentrainment in peripheral clocks.

    2. Photobiological Interactions of Blue Light and Photosynthetic Photon Flux: Effects of Monochromatic and Broad-Spectrum Light Sources

      Kevin R. Cope, M. Chase Snowden and Bruce Bugbee

      Article first published online: 18 JAN 2014 | DOI: 10.1111/php.12233

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      Blue light (BL) has profound effects on leaf expansion and stem elongation but the interactions of BL with other wavelengths of photosynthetically active radiation and with total PPF are poorly characterized. We used three broad-spectrum and four monochromatic LED arrays at two photosynthetic photon flux (PPF) to quantify BL effects on plant growth and development. Regardless of PPF, BL was necessary to prevent shade-avoidance responses in lettuce and radish but not pepper. Leaf expansion was altered by a unique interaction of BL with PPF. Surprisingly, there were few additional interactions of BL between monochromatic and broad-spectrum light sources.

    3. Photoacclimation Responses of the Brown Macroalga Sargassum Cymosum to the Combined Influence of UV Radiation and Salinity: Cytochemical and Ultrastructural Organization and Photosynthetic Performance

      Luz K. Polo, Marthiellen R. de L. Felix, Marianne Kreusch, Debora T. Pereira, Giulia B. Costa, Carmen Simioni, Luciane C. Ouriques, Fungyi Chow, Fernanda Ramlov, Marcelo Maraschin, Zenilda L. Bouzon and Éder C. Schmidt

      Article first published online: 10 JAN 2014 | DOI: 10.1111/php.12224

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      The figure shows the brown macroalga Sargassum cymosum have protective mechanism against oxidative stress, making defense against UVR more efficient. After exposure to UVR, S. cymosum increased cell wall thickness, physodes and presence of phenolic compounds.

    4. Inactivation of Bacteriophage Infecting Bacteroides Strain GB124 Using UV-B Radiation

      David Diston, James E. Ebdon and Huw D. Taylor

      Article first published online: 10 JAN 2014 | DOI: 10.1111/php.12223

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      Bacteriophage infecting Bacteroides fragilis strain GB-124 are a useful tool in determining the source of fecal pollution within aquatic environments. Here we present insights into the UV-B inactivation ecology of this important phage group by conducting controlled laboratory collimated-beam UV-B irradiation experiments. Results indicate that B124 phage may be inactivated at levels of UV-B commonly recorded in the environment, and inactivation potential should be considered when interpreting environmental B124 phage data.

    5. Role of Ozone in UV-C Disinfection, Demonstrated by Comparison between Wild-Type and Mutant Conidia of Aspergillus niger

      Jing Liu, Lin Zhou, Ji-Hong Chen, Wang Mao, Wen-Jian Li, Wei Hu, Shu-Yang Wang and Chun-Ming Wang

      Article first published online: 7 JAN 2014 | DOI: 10.1111/php.12217

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      The effect of UV light was divided into two parts: UV irradiation and the concomitantly generated ozone. The role of ozone in the disinfection of UV–C was illustrated through comparing wild-type (CON1) and mutant (MUT1) Aspergillus niger conidia. The results indicated that melanin protected A. niger against UV disinfection in two ways: absorbing UV light (UV screening) and scavenging free radicals. The synergistic effect of UV irradiation and ozone exhibited the most potent fungicidal results. So the direct exposure to UV irradiation and ozone were both necessary for thorough disinfection.

  15. Research Notes

    1. Photosensitized Damage Inflicted on Plasma Membranes of Live Cells by An Extracellular Generator of Singlet Oxygen—A Linear Dependence of A Lethal Dose on Light Intensity

      Mirosław Zarębski, Magdalena Kordon and Jurek W. Dobrucki

      Article first published online: 6 JAN 2014 | DOI: 10.1111/php.12216

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      The influence of a dose rate, i.e. light intensity or photon flux, on the efficiency of induction of a photosensitized loss of integrity of plasma membranes of live cells in culture is described. We demonstrate that the size of the lethal dose of light is directly proportional to the intensity of the exciting light. Thus, the probability of a photon of the exciting light inflicting photosensitized damage on plasma membranes diminishes with increasing density of the incident photons.

  16. Research Articles

    1. Triplet–Triplet Energy Transfer from a UV-A Absorber Butylmethoxydibenzoylmethane to UV-B Absorbers

      Azusa Kikuchi, Nozomi Oguchi-Fujiyama, Kazuyuki Miyazawa and Mikio Yagi

      Article first published online: 6 JAN 2014 | DOI: 10.1111/php.12222

      Thumbnail image of graphical abstract

      The intermolecular triplet–triplet energy transfer from 4-tert-butyl-4′-methoxydibenzolymethane (BMDBM) to octocrylene (OCR) has been observed by measuring the phosphorescence decay of BMDBM following a 355 nm laser excitation. The lifetime of the lowest excited triplet state of BMDBM is significantly reduced in the presence of OCR. Our methodology of energy-donor phosphorescence decay measurements can be applied to the study of the triplet–triplet energy transfer between UV absorbers even if the energy acceptor is nonphosphorescent.

    2. Scrambled Self-Assembly of Bacteriochlorophylls c and e in Aqueous Triton X-100 Micelles

      Yoshitaka Saga, Tatsuya Saiki, Naoya Takahashi, Yutaka Shibata and Hitoshi Tamiaki

      Article first published online: 24 DEC 2013 | DOI: 10.1111/php.12219

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      Bacteriochlorophyll (BChl) e was coassembled with BChl c in Triton X-100 micelles in aqueous solutions. The spectral features and the decomposition behaviors of the scrambled self-aggregates suggest that BChls c and e are not spatially separated; they are homogenously distributed over the self-aggregates to give electronic spectra that are different from those of the aggregate consisting solely of each pigment.

    3. Antimicrobial Photodynamic Efficiency of Novel Cationic Porphyrins towards Periodontal Gram-positive and Gram-negative Pathogenic Bacteria

      Chandra Sekhar Prasanth, Suneesh C. Karunakaran, Albish K. Paul, Vesselin Kussovski, Vanya Mantareva, Danaboyina Ramaiah, Leslie Selvaraj, Ivan Angelov, Latchezar Avramov, Krishnankutty Nandakumar and Narayanan Subhash

      Article first published online: 17 DEC 2013 | DOI: 10.1111/php.12198

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      We describe the synthesis and in vitro photodyanamic activity of two cationic porphyrin derivatives using Gram-positive as well as Gram-negative bacteria. These porphyrin derivatives exhibited favorable photophysical properties including high quantum yields of the triplet excited state and singlet oxygen generation efficiency. Furthermore, the in vitro studies indicated that these derivatives accumulate into bacterial cells and biofilms, and exhibit high antibacterial activity upon NIR excitation. Our results demonstrate that these cationic porphyrins can act as sensitizers for effective photoinactivation of bacterial strains associated with periodontitis and thereby their potential application in antibacterial photodynamic therapy.

    4. Reflectance and Cyclic Electron Flow as an Indicator of Drought Stress in Cotton (Gossypium hirsutum)

      Ruchi Singh, Jishnu Naskar, Uday V. Pathre and Pramod A. Shirke

      Article first published online: 14 DEC 2013 | DOI: 10.1111/php.12213

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      We observed that in Gossypium hirsutum, during water limitation, Chlorophyll b showed the best correlation with reflectance at 731 nm and is a good indicator of drought. During mild water stress photosystem I and photosystem II is protected from photoinhibition by high cyclic electron flow (CEF) and nonphotochemical quenching. While during severe drought stress, linear electron flow decreases sharply in comparison to CEF. CEF play a major role in G. hirsutum leaves during mild as well as under severe water stresses and is thus a good indicator of drought.

    5. Photoinhibition of Cyanobacteria and its Application in Cultural Heritage Conservation

      Paul Hsieh, Jens Z. Pedersen and Laura Bruno

      Article first published online: 10 DEC 2013 | DOI: 10.1111/php.12208

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      To our knowledge, we are the first group that applies photoinhibition in the field of cultural heritage conservation. Because cyanobacteria are rich in Chl a and phycobiliproteins that can be excited by light to generate ROS, exposure of cyanobacteria to light beyond the turnover intensity may result in photoinhibition of photosynthesis, photobleaching of pigments and photodamage to the cells. Practically, red, green or white illumination can be tested at night in situ in the dim catacombs, caves and underground chambers, without disturbing the tourists, and without introducing any harmful chemicals to humans, to environment, or to the cultural heritage.

    6. Gold Nanorod-Assembled PEGylated Graphene-Oxide Nanocomposites for Photothermal Cancer Therapy

      Uuriintuya Dembereldorj, Seon Young Choi, Erdene-Ochir Ganbold, Nam Woong Song, Doseok Kim, Jaebum Choo, So Yeong Lee, Sehun Kim and Sang-Woo Joo

      Article first published online: 5 DEC 2013 | DOI: 10.1111/php.12212

      Thumbnail image of graphical abstract

      Gold nanorod-attached PEGylated graphene-oxide nanocomposites were tested for a photothermal platform both in vitro and in vivo.

    7. Hydrogel-Forming and Dissolving Microneedles for Enhanced Delivery of Photosensitizers and Precursors

      Ryan F. Donnelly, Desmond I. J. Morrow, Maelíosa T. C. McCrudden, Ahlam Zaid Alkilani, Eva M. Vicente-Pérez, Conor O'Mahony, Patricia González-Vázquez, Paul A. McCarron and A. David Woolfson

      Article first published online: 5 DEC 2013 | DOI: 10.1111/php.12209

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      We present novel dissolving and hydrogel-forming microneedle arrays (MN) that can be applied in a one-step fashion and are intended to enhance delivery of photosensitizers and photosensitizer precursors. Both dissolving and hydrogel-forming MN proved effective in in vitro studies and we are now proceeding with animal investigations prior to preliminary human evaluation of technology with the potential to improve therapeutic outcomes for patients with nodular skin lesions.

    8. Effect of Laser Phototherapy on Enzymatic Activity of Salivary Glands of Hamsters Treated with 5-Fluorouracil

      Luana Campos, José Nicolau, Victor E. Arana-Chavez and Alyne Simões

      Article first published online: 28 NOV 2013 | DOI: 10.1111/php.12195

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      The chemotherapeutic agent 5-Fluorouracil clearly affects the submandibular and sublingual glands function, causing an increase in the activity of lactate dehydrogenase and antioxidant enzymes, such as catalase and peroxidase, as well as a decrease in superoxide dismutase activity of glands; however, the LPT is a promising therapy to modulate these harmful effects.

    9. Energy Harvesting Capability of Lipid-Merocyanine Macromolecules: A New Design and Performance Model Development

      Lobat Tayebi, Masoud Mozafari, Rita El-khouri, Parvaneh Rouhani and Daryoosh Vashaee

      Article first published online: 28 NOV 2013 | DOI: 10.1111/php.12193

      Thumbnail image of graphical abstract

      Capacitor charging time reduced and open circuit voltage enhanced significantly in the newly designed lipid-merocyanine photoelectrochemical cell.

    10. Kinetics of Photosynthetic Response to Ultraviolet and Photosynthetically Active Radiation in Synechococcus WH8102 (CYANOBACTERIA)

      Glaucia M. Fragoso, Patrick J. Neale, Todd M. Kana and Alicia L. Pritchard

      Article first published online: 28 NOV 2013 | DOI: 10.1111/php.12202

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      We studied the responses of PSII quantum yield, carbon fixation and oxygen evolution in Synechococcus WH8102 under levels of PAR and UVR that are representative of a mixed layer from oligotrophic waters. Fluorescence kinetics measurements showed that these radiation levels inhibited PSII activity, however, an apparent induction of photoprotection was observed. Although oxygen uptake is a mechanism of photoprotection when cells are exposed to increase levels of PAR, our results show that this is not an important strategy against UVR.

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