keyword
MENU ▼
Read by QxMD icon Read
search

Photosensitisers

keyword
https://www.readbyqxmd.com/read/28185089/effectiveness-of-repeated-photodynamic-therapy-in-the-elimination-of-intracanal-enterococcus-faecalis-biofilm-an-in-vitro-study
#1
Ewa Joanna Prażmo, Renata Alicja Godlewska, Agnieszka Beata Mielczarek
The study aimed to investigate the effectiveness of photodynamic therapy in the elimination of intracanal Enterococcus faecalis biofilm and to analyse how a repeated light irradiation, replenishment of oxygen and photosensitiser affect the results of the photodynamic disinfecting protocol. After chemomechanical preparation, 46 single-rooted human teeth were infected with a clinical strain of E. faecalis and incubated for a week in microaerobic conditions. The experimental procedures included groups of single application of photodynamic therapy, two cycles of PDT, irrigation with 5...
February 10, 2017: Lasers in Medical Science
https://www.readbyqxmd.com/read/28176995/evidence-for-photosensitised-hydrogen-production-from-water-in-the-absence-of-precious-metals-redox-mediators-and-co-catalysts
#2
S Salzl, M Ertl, G Knör
The water-soluble zinc porphyrin complex Zn(TPPS)(4-) with TPPS = tetrakis-(4-sulfonatophenyl)porphyrin surprisingly was found to produce significant amounts of hydrogen from aqueous sulfite or amine solutions under visible-light exposure without requiring any other components such as electron relays or additional proton reduction catalysts. Although the production rates and total amounts of chemically stored fuel obtained under these conditions are still much too low to be relevant for practical applications, the background of this unprecedented observation was further studied in its own right...
February 8, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28127949/glycolysis-inhibition-improves-photodynamic-therapy-response-rates-for-equine-sarcoids
#3
J P Golding, J G Kemp-Symonds, J M Dobson
Photodynamic therapy (PDT) holds great promise in treating veterinary and human dermatological neoplasms, including equine sarcoids, but is currently hindered by the amount of photosensitiser and light that can be delivered to lesions thicker than around 2 mm, and by the intrinsic antioxidant defences of tumour cells. We have developed a new PDT technique that combines an efficient transdermal penetration enhancer solution, for topical delivery of 5-aminolevulinic acid (ALA) photosensitiser, with acute topical post-PDT application of the glycolysis inhibitor lonidamine...
January 27, 2017: Veterinary and Comparative Oncology
https://www.readbyqxmd.com/read/28067647/decomposition-of-xenobiotics-during-visible-light-irradiation-in-the-presence-of-immobilised-photosensitisers-kinetics-study
#4
M Olak-Kucharczyk, M Foszpańczyk, M Gmurek, S Ledakowicz
The objective of this work was to study the photosensitised oxidation of the xenobiotics benzylparaben (BeP) and 2,4dichlorophenol (2,4DCP) in aqueous solutions using photosensitisers immobilised into chitosan carrier particles and visible light radiation. Zn(II) phthalocyanine tetrasulfonate tetrasodium salt and Al(III) phthalocyanine chloride tetrasulfonic acid were used as photosensitisers. The major role of the singlet oxygen during photodegradation was proven by using scavengers of reactive oxygen species...
January 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
https://www.readbyqxmd.com/read/28063989/deep-penetrating-photodynamic-therapy-with-killerred-mediated-by-upconversion-nanoparticles
#5
Liuen Liang, Yiqing Lu, Run Zhang, Andrew Care, Tiago A Ortega, Sergey M Deyev, Yi Qian, Andrei V Zvyagin
: The fluorescent protein KillerRed, a new type of biological photosensitizer, is considered as a promising substitute for current synthetic photosensitizes used in photodynamic therapy (PDT). However, broad application of this photosensitiser in treating deep-seated lesions is challenging due to the limited tissue penetration of the excitation light with the wavelength falling in the visible spectral range. To overcome this challenge, we employ upconversion nanoparticles (UCNPs) that are able to convert deep-penetrating near infrared (NIR) light to green light to excite KillerRed locally, followed by the generation of reactive oxygen species (ROS) to kill tumour cells under centimetre-thick tissue...
January 4, 2017: Acta Biomaterialia
https://www.readbyqxmd.com/read/27989755/oxidatively-generated-damage-to-dna-and-proteins-mediated-by-photosensitized-uva
#6
REVIEW
Reto Brem, Melisa Guven, Peter Karran
UVA accounts for about 95% of the solar ultraviolet (UV) radiation that reaches Earth and most likely contributes to human skin cancer risk. In contrast to UVB, which comprises the remaining 5% and is absorbed by DNA nucleobases to cause direct photodamage, UVA damages DNA indirectly. It does this largely through its interactions with cellular chromophores that act as photosensitisers to generate reactive oxygen species. Exogenously supplied chemicals, including some widely-prescribed medicines, may also act as photosensitisers and these drugs are associated with an increased risk of sun-related cancer...
October 27, 2016: Free Radical Biology & Medicine
https://www.readbyqxmd.com/read/27886311/flexible-synthesis-of-cationic-peptide-porphyrin-derivatives-for-light-triggered-drug-delivery-and-photodynamic-therapy
#7
R Dondi, E Yaghini, K M Tewari, L Wang, F Giuntini, M Loizidou, A J MacRobert, I M Eggleston
Efficient syntheses of cell-penetrating peptide-porphyrin conjugates are described using a variety of bioconjugation chemistries. This provides a flexible means to convert essentially hydrophobic tetrapyrolle photosensitisers into amphiphilic derivatives which are well-suited for use in light-triggered drug delivery by photochemical internalisation (PCI) and targeted photodynamic therapy (PDT).
December 7, 2016: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/27782094/photodynamic-therapy-and-non-melanoma-skin-cancer
#8
REVIEW
Liezel L Griffin, John T Lear
Non-melanoma skin cancer (NMSC) is the most common malignancy among the Caucasian population. Photodynamic therapy (PDT) is gaining popularity for the treatment of basal cell carcinoma (BCC), Bowen's disease (BD) and actinic keratosis (AK). A topical or systemic exogenous photosensitiser, results in selective uptake by malignant cells. Protoporphyrin IX (PpIX) is produced then activated by the introduction of a light source. Daylight-mediated MAL (methyl aminolaevulinate) PDT for AKs has the advantage of decreased pain and better patient tolerance...
October 22, 2016: Cancers
https://www.readbyqxmd.com/read/27775926/polyethylene-glycol-coated-blue-emitting-silicon-dots-with-improved-properties-for-uses-in-aqueous-and-biological-environments
#9
Damián Rodríguez Sartori, Cristian R Lillo, Juan J Romero, María Laura Dell Arciprete, Alejandro Miñán, Mónica Fernández Lorenzo de Mele, Mónica C Gonzalez
Grafting of polyethylene glycol (PEG) to ultrasmall photoluminescent silicon dots (SiDs) is expected to improve and expand the applications of these particles to aqueous environments and biological systems. Herein we report a novel one-pot synthesis of robust, highly water compatible PEG-coated SiDs (denoted as PEG-SiDs) of (3.3 ± 0.5) nm size. The nanoparticles' synthesis is based on the liquid phase oxidation of magnesium silicide using PEG as reaction media and leading to high PEG density grafting. PEG-SiDs enhanced photophysical, photosensitising, and solution properties in aqueous environments are described and compared to those of 2 nm size PEG-coated SiDs with low PEG density grafting (denoted as PEG-NHSiDs) obtained from a multistep synthesis strategy...
October 24, 2016: Nanotechnology
https://www.readbyqxmd.com/read/27731350/riboflavin-photoactivation-by-upconversion-nanoparticles-for-cancer-treatment
#10
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
https://www.readbyqxmd.com/read/27722413/visible-light-dye-photosensitised-oxidation-of-pyrroles-using-a-simple-led-photoreactor
#11
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
https://www.readbyqxmd.com/read/27722271/comparative-study-of-singlet-oxygen-production-by-photosensitiser-dyes-encapsulated-in-silicone-towards-rational-design-of-anti-microbial-surfaces
#12
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
https://www.readbyqxmd.com/read/27696302/electrosprayed-janus-particles-for-combined-photo-chemotherapy
#13
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
https://www.readbyqxmd.com/read/27622274/two-dimensional-artificial-light-harvesting-antennae-with-predesigned-high-order-structure-and-robust-photosensitising-activity
#14
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
https://www.readbyqxmd.com/read/27619739/duramycin-porphyrin-conjugates-for-targeting-of-tumour-cells-using-photodynamic-therapy
#15
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
https://www.readbyqxmd.com/read/27595652/intracellular-haemolytic-agents-of-heterocapsa-circularisquama-exhibit-toxic-effects-on-h-circularisquama-cells-themselves-and-suppress-both-cell-mediated-haemolytic-activity-and-toxicity-to-rotifers-brachionus-plicatilis
#16
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
https://www.readbyqxmd.com/read/27593392/acute-photosensitisation-and-mortality-in-a-herd-of-dairy-cattle-in-tasmania
#17
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...
January 2017: New Zealand Veterinary Journal
https://www.readbyqxmd.com/read/27566444/interplay-between-membrane-lipid-peroxidation-and-photoproduct-formation-in-the-ultraviolet-a-induced-phototoxicity-of-vemurafenib-in-skin-keratinocytes
#18
Ana Teixeira, Patrice Morlière, João Ferreira, Marie-Alix Conte, Antoine Galmiche, Jean-Claude Mazière, René Santus, Paulo Filipe
According to some authors, the phototoxic response to ultraviolet A (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 work is aimed at determining the contribution of reactive oxygen species (ROS), lipid photoperoxidation, and VB photochemistry in the UVA-induced photocytotoxicity in NCTC 2544 keratinocytes. The potent membrane lipid peroxidation effectiveness of VB-photosensitization has been proved by the observation of an effective photohemolysis accompanied by thiobarbituric reactive substances (TBARS) formation in 2% red blood cell (RBC) suspensions...
December 2016: Toxicological Sciences: An Official Journal of the Society of Toxicology
https://www.readbyqxmd.com/read/27546513/-photodynamic-modulation-of-cellular-functions
#19
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]
https://www.readbyqxmd.com/read/27501936/a-her2-selective-theranostic-agent-for-surgical-resection-guidance-and-photodynamic-therapy
#20
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
keyword
keyword
1045
1
2
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"