Read by QxMD icon Read


E V Khaydukov, K E Mironova, V A Semchishen, A N Generalova, A V Nechaev, D A Khochenkov, E V Stepanova, O I Lebedev, A V Zvyagin, S M Deyev, V Ya Panchenko
Riboflavin (Rf) is a vitamin and endogenous photosensitizer capable to generate reactive oxygen species (ROS) under UV-blue irradiation and kill cancer cells, which are characterized by the enhanced uptake of Rf. We confirmed its phototoxicity on human breast adenocarcinoma cells SK-BR-3 preincubated with 30-μM Rf and irradiated with ultraviolet light, and proved that such Rf concentrations (60 μM) are attainable in vivo in tumour site by systemic intravascular injection. In order to extend the Rf photosensitization depth in cancer tissue to 6 mm in depth, we purpose-designed core/shell upconversion nanoparticles (UCNPs, NaYF4:Yb(3+):Tm(3+)/NaYF4) capable to convert 2% of the deeply-penetrating excitation at 975 nm to ultraviolet-blue power...
October 12, 2016: Scientific Reports
James K Howard, Kieran J Rihak, Christopher J T Hyland, Alex C Bissember, Jason A Smith
The photooxidation of pyrrole is typically low yielding due to the absorbance of ultraviolet light, which leads to uncontrolled polymerisation and decomposition. Presented herein is the development of a simple and cost-effective photoreactor utilising Light Emitting Diodes (LEDs) as the light source, and its application to the dye-sensitised oxidation of a range of pyrroles to give corresponding 3-pyrrolin-2-ones. The broader applicability of this approach to the generation of (1)O2 is also explored.
September 21, 2016: Organic & Biomolecular Chemistry
Sacha Noimark, Enrico Salvadori, Rafael Gómez-Bombarelli, Alexander J MacRobert, Ivan P Parkin, Christopher W M Kay
Surfaces with built-in antimicrobial activity have the potential to reduce hospital-acquired infections. One promising strategy is to create functionalised surfaces which, following illumination with visible light, are able to generate singlet oxygen under aerobic conditions. In contrast to antibiotics, the mechanism of bacterial kill by species derived from reactions with singlet oxygen is completely unselective, therefore offering little room for evolutionary adaptation. Here we consider five commercially available organic photosensitiser dyes encapsulated in silicone polymer that show varied antimicrobial activity...
October 12, 2016: Physical Chemistry Chemical Physics: PCCP
Brenda Sanchez-Vazquez, Adérito J R Amaral, Deng-Guang Yu, George Pasparakis, Gareth R Williams
This work is a proof of concept study establishing the potential of electrosprayed Janus particles for combined photodynamic therapy-chemotherapy. Sub-micron-sized particles of polyvinylpyrrolidone containing either an anti-cancer drug (carmofur) or a photosensitiser (rose bengal; RB), and Janus particles containing both in separate compartments were prepared. The functional components were present in the amorphous form in all the particles, and infrared spectroscopy indicated that intermolecular interactions formed between the different species...
September 30, 2016: AAPS PharmSciTech
Xiao Feng, Xuesong Ding, Long Chen, Yang Wu, Lili Liu, Matthew Addicoat, Stephan Irle, Yuping Dong, Donglin Jiang
Highly ordered discrete assemblies of chlorophylls that are found in natural light-harvesting antennae are key to photosynthesis, which converts light energy to chemical energy and is the principal producer of organic matter on Earth. Porphyrins and phthalocyanines, which are analogues of chlorophylls, exhibit a strong absorbance of visible and near-infrared light, respectively. A highly ordered porphyrin-co-phthalocyanine antennae would harvest photons over the entire solar spectrum for chemical transformation...
2016: Scientific Reports
Laura J Broughton, Francesca Giuntini, Huguette Savoie, Francesca Bryden, Ross W Boyle, Anthony Maraveyas, Leigh A Madden
Duramycin, through binding with phosphatidylethanolamine (PE), has been shown to be a selective molecular probe for the targeting and imaging of cancer cells. Photodynamic therapy aims to bring about specific cytotoxic damage to tumours through delivery of a photosensitising agent and light irradiation. Conjugation to biological molecules that specifically target cancer has been shown to increase photosensitiser (PS) selectivity and decrease damage to surrounding normal tissue. The aim of this study was to target tumour cells with a PE-specific PS therefore duramycin was conjugated to a porphyrin based PS which was achieved via direct reaction with the ε-amino group on the lysine residue near duramycin's N-terminal...
October 2016: Journal of Photochemistry and Photobiology. B, Biology
Tomoki Nishiguchi, Kichul Cho, Masumi Yasutomi, Mikinori Ueno, Kenichi Yamaguchi, Leila Basti, Yasuhiro Yamasaki, Satoshi Takeshita, Daekyung Kim, Tatsuya Oda
A harmful dinoflagellate, Heterocapsa circularisquama, is highly toxic to shellfish and the zooplankton rotifer Brachionus plicatilis. A previous study found that H. circularisquama has both light-dependent and -independent haemolytic agents, which might be responsible for its toxicity. Detailed analysis of the haemolytic activity of H. circularisquama suggested that light-independent haemolytic activity was mediated mainly through intact cells, whereas light-dependent haemolytic activity was mediated by intracellular agents which can be discharged from ruptured cells...
October 2016: Aquatic Toxicology
H M Golder, N Moss, G Rogers, B Jackson, N Gannon, Ptw Wong, I J Lean
CASE HISTORY: A herd of Holstein, Jersey, or Holstein-Jersey cross lactating cattle of mixed ages presented with a sudden drop in milk yield in 94/678 cows on 3 October 2014 (Day 0). The herd was located in Gretna in the Derwent Valley (Tasmania, Australia) and had been grazing dryland pasture. CLINICAL FINDINGS: On Day 0 the cows variably showed recumbency, peracute photosensitisation, inflamed coronary bands, conjunctival erythema, periauricular oedema, distress indicated by kicking at the flank, bruxism, discomfort, weight shifting, vocalisation indicating pain and depression...
October 2, 2016: New Zealand Veterinary Journal
A Teixeira, P Morlière, J Ferreira, M-A Conte, A Galmiche, J-C Mazière, R Santus, P Filipe
According to some authors, the phototoxic response to UVA of patients treated with vemurafenib (VB) may involve VB metabolites. However, the production of singlet oxygen and free radicals and photoproduct formation upon UVA light absorption by the lipophilic VB have been demonstrated. This works is aimed at determining the contribution of reactive oxygen species (ROS), lipid photoperoxidation and VB photochemistry in the UVA-induced photocytotoxicity in 2544 NCTC keratinocytes. The potent membrane lipid peroxidation effectiveness of VB-photosensitisation has been proved by the observation of an effective photohaemolysis accompanied by thiobarbituric reactive substances (TBARS) formation in 2% red blood cell (RBC) suspensions...
August 26, 2016: Toxicological Sciences: An Official Journal of the Society of Toxicology
Yuan Li, Hong-Ning Jiang, Zong-Jie Cui
Photodynamic action, due to the rather limited lifetime (1 μs) and effective reactive distance of singlet oxygen (< 10 nm), could subcellular-specifically regulate different cellular functions. Photodynamic action could activate permanently cholecystokinin (CCK) 1 receptors, and sensitize or desensitize other G protein-coupled receptors. The emergence in recent years of genetically- encoded protein photosensitisers has enabled more precisely-targeted photodynamic modulation of subcellular organelles and functional proteins...
August 25, 2016: Sheng Li Xue Bao: [Acta Physiologica Sinica]
H Pye, M A Butt, H W Reinert, A Maruani, J P M Nunes, J S Marklew, M Qurashi, L Funnell, A May, I Stamati, R Hamoudi, J R Baker, M E B Smith, S Caddick, M P Deonarain, G Yahioglu, V Chudasama, L B Lovat
In many cancers early intervention involves surgical resection of small localised tumour masses. Inadequate resection leads to recurrence whereas overzealous treatment can lead to organ damage. This work describes production of a HER2 targeting antibody Fab fragment dual conjugated to achieve both real time near-infrared fluorescent imaging and photodynamic therapy. The use of fluorescence emission from a NIR-dye could be used to guide resection of tumour bulk, for example during endoscopic diagnosis for oesophago-gastric adenocarcinoma, this would then be followed by activation of the photodynamic therapeutic agent to destroy untreated localised areas of cancer infiltration and tumour infiltrated lymph nodes...
October 5, 2016: Photochemical & Photobiological Sciences
Aurimas Vyšniauskas, Maryam Qurashi, Marina K Kuimova
Oxidation of cellular structures is typically an undesirable process that can be a hallmark of certain diseases. On the other hand, photooxidation is a necessary step of photodynamic therapy (PDT), a cancer treatment causing cell death upon light irradiation. Here, the effect of photooxidation on the microscopic viscosity of model lipid bilayers constructed of 1,2-dioleoyl-sn-glycero-3-phosphocholine has been studied. A molecular rotor has been employed that displays a viscosity-dependent fluorescence lifetime as a quantitative probe of the bilayer's viscosity...
September 5, 2016: Chemistry: a European Journal
Ahmed A Sultan, Waseem Jerjes, Kristian Berg, Anders Høgset, Charles A Mosse, Rifat Hamoudi, Zaid Hamdoon, Celia Simeon, Dawn Carnell, Martin Forster, Colin Hopper
BACKGROUND: Photochemical internalisation, a novel minimally invasive treatment, has shown promising preclinical results in enhancing and site-directing the effect of anticancer drugs by illumination, which initiates localised chemotherapy release. We assessed the safety and tolerability of a newly developed photosensitiser, disulfonated tetraphenyl chlorin (TPCS2a), in mediating photochemical internalisation of bleomycin in patients with advanced and recurrent solid malignancies. METHODS: In this phase 1, dose-escalation, first-in-man trial, we recruited patients (aged ≥18 to <85 years) with local recurrent, advanced, or metastatic cutaneous or subcutaneous malignancies who were clinically assessed as eligible for bleomycin chemotherapy from a single centre in the UK...
September 2016: Lancet Oncology
Yuktee Dogra, Daniel C J Ferguson, Nicholas J F Dodd, Gary R Smerdon, Alison Curnow, Paul G Winyard
Methyl-aminolevulinate-based photodynamic therapy (MAL-PDT) is utilised clinically for the treatment of non-melanoma skin cancers and pre-cancers and the hydroxypyridinone iron chelator, CP94, has successfully been demonstrated to increase MAL-PDT efficacy in an initial clinical pilot study. However, the biochemical and photochemical processes leading to CP94-enhanced photodynamic cell death, beyond the well-documented increases in accumulation of the photosensitiser protoporphyrin IX (PpIX), have not yet been fully elucidated...
July 7, 2016: Redox Biology
Nela Malatesti, Anja Harej, Sandra Kraljević Pavelić, Martin Lončarić, Hrvoje Zorc, Karlo Wittine, Uros Andjelkovic, Djuro Josic
Photodynamic therapy (PDT) is a treatment that aims to kill cancer cells by reactive oxygen species, mainly singlet oxygen, produced through light activation of a photosensitiser (PS). Amongst photosensitisers that attracted the most attention in the last decade are cationic and amphiphilic molecules based on porphyrin, chlorin and phthalocyanine structures. Our aim was to join this search for more optimal balance of the lipophilic and hydrophilic moieties in a PS. A new amphiphilic porphyrin, 5-(4-octadecanamidophenyl)-10,15,20-tris(N-methylpyridinium-3-yl)porphyrin trichloride (5) was synthesised and characterised by (1)H NMR, UV-vis and fluorescence spectroscopy, and by MALDI-TOF/TOF spectrometry...
September 2016: Photodiagnosis and Photodynamic Therapy
R Revathi, A Rameshkumar, T Sivasudha
The combination of nanoparticles with the photosensitizing molecules will assist in developing new approach for their biological applications. In this paper work, we have studied the interaction of photosensitising mesotetrakis (2,6,dimethoxyphenol) porphyrin molecule (P1) with AuTiO2 nanoparticles using absorption, fluorescence and time resolved measurements. An isosbestic point is appeared in the absorption spectrum of P1 on increasing the concentration of AuTiO2 nanoparticles indicates the interaction of P1 with AuTiO2 nanoparticles...
June 2016: Journal of Nanoscience and Nanotechnology
Sun Y S Chow, Pui-Chi Lo, Dennis K P Ng
An acetal-linked self-quenched zinc(ii) phthalocyanine tetramer has been prepared. In an acidic environment in phosphate buffered saline or inside tumour cells, the phthalocyanine units of the tetramer are separated thereby restoring the fluorescence emission and singlet oxygen production. This response enables this compound to serve as a promising activatable photosensitiser for photodynamic therapy.
August 16, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Ioana Baldea, Diana Elena Olteanu, Pompei Bolfa, Flaviu Tabaran, Rodica-Mariana Ion, Gabriela Adriana Filip
Melanoma, a cancer derived from melanocytes is very difficult to treat, especially in advanced cases. There are several encouraging studies of the efficacy of photodynamic therapy (PDT) in melanoma. However, PDT has to overcome the main defense mechanisms like: defects in the apoptotic pathways, pigmentation, sequestration of the photosensitisers (PS) inside melanosomes and increased oxidative stress defense. Two meso-substituted porphyrins, meso-5,10,15,20-tetrakis (4-hydroxyphenyl) porphyrin (THOPP) and meso-5-(4-hydroxyphenyl)-10, 15, 20-tris (4-methoxyphenyl) porphyrin (THOMPP) were used as PS to investigate several mechanisms underlining the PDT anti-melanoma effects, on a lightly pigmented melanoma cell line (WM35), in vitro...
August 2016: Journal of Photochemistry and Photobiology. B, Biology
Yusuke Tamaki, Daisuke Imori, Tatsuki Morimoto, Kazuhide Koike, Osamu Ishitani
Photocatalytic systems for CO2 reduction using a Ru(ii) tris-diimine complex (Ru) as a photosensitiser and dinuclear Re(i) diimine tricarbonyl complexes (Re(n)Re), in which diimine ligands are connected by alkyl chains of various lengths (-CnH2n-: n = 2, 3, 4, 6, 14), as catalysts were investigated. The photocatalytic systems using Re(n)Re exhibited improved durability compared with that using the corresponding mononuclear Re(i) complex (Re); moreover, among the Re(n)Re, shorter alkyl chains in the bridging ligands induced greater durability...
October 7, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Z Jiyad, C M Olsen, M T Burke, N M Isbel, A C Green
Azathioprine, a purine antimetabolite immunosuppressant, photosensitizes the skin and causes the production of mutagenic reactive oxygen species. It is postulated to increase the risk of squamous cell carcinoma (SCC) and other skin cancers in organ transplant recipients (OTRs), but evidence from multiple, largely single-center studies to date has been inconsistent. We aimed to resolve the issue of azathioprine's carcinogenicity by conducting a systematic review of the relevant literature and pooling published risk estimates to evaluate the risks of SCC, basal cell carcinoma (BCC), keratinocyte cancers (KCs) overall and other skin cancers in relation to azathioprine treatment...
May 10, 2016: American Journal of Transplantation
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"