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Shi Gao, Guohao Wang, Zainen Qin, Xiangyu Wang, Guoqing Zhao, Qingjie Ma, Lei Zhu
Photodynamic therapy (PDT) is a promising tumor treatment modality that can convert oxygen into cytotoxic singlet oxygen (SO) via photosensitizer to ablate tumor growth. However, the uncontrolled cancer cell proliferation during tumor development and the oxygen consumption during PDT always result in an insufficient oxygen level in tumors, which can adversely affect the PDT efficiency in turn. We designed an oxygen-generating PDT nanocomplex by encapsulating a manganese dioxide nanoparticle (MnO2 NP) in an indocyanine green (ICG) modified hyaluronic acid nanoparticle (HANP) to overcome this limitation...
October 19, 2016: Biomaterials
Jean-Baptiste Tylcz, Thierry Bastogne, Alexia Bourguignon, Celine Frochot, Muriel Barberi-Heyob
: Photodynamic therapy (PDT) is an alternative treatment for cancer that involves the administration of a photosensitizing agent, which is activated by light at a specific wavelength. This illumination causes after a sequence of photoreactions, the production of reactive oxygen species responsible for the death of the tumor cells but also the degradation of the photosensitizing agent, which then loose the fluorescence properties. The phenomenon is commonly known as photobleaching process and can be considered as a therapy efficiency indicator...
October 21, 2016: IEEE Transactions on Bio-medical Engineering
Takuro Ikeuchi, John Mack, Tebello A Nyokong, Nagao Kobayashi, Mutsumi Kimura
A water-soluble zinc phthalocyanine (ZnPc) complex with four negatively charged electron-withdrawing sulfonic acid substituents at the non-peripheral positions (-ZnTSPc) is found to have a high singlet oxygen (1O2) quantum yield and displays high photostability, since the formation of aggregates is hindered and the HOMO is significantly stabilized, this making -ZnTSPc potentially suitable for use as a photosensitizer for photodynamic therapy and photoimmunotherapy. Atomic force microscopy (AFM) reveals that mixtures of the negatively charged -ZnTSPc complex with a similar positively charged ZnPc were found to result in the self-assembly of one-dimensional accordion-like fibers...
October 24, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Wan-Yi Li, Xia Li, Steffen Jockusch, Han Wang, Bolei Xu, Yajing Wu, William Gang Tsui, Hai-Lung Dai, V Faye McNeill, Yi Rao
Photoactivated reactions of organic species in atmospheric aerosol particles are a potentially significant source of secondary organic aerosol material (SOA). Despite recent progress, the dominant chemical mechanisms and rates of these reactions remain largely unknown. In this work, we characterize the photo-physical properties and photochemical reaction mechanisms of imidazole-2-carboxaldehyde (IC) in aqueous solution, alone and in the presence of isoprene. IC has been shown previously in laboratory studies to participate in photoactivated chemistry in aerosols, and is a known in-particle reaction product of glyoxal...
October 24, 2016: Journal of Physical Chemistry. A
Athanassios Panagiotopoulos, Antonios M Douvas, Panagiotis Argitis, Athanassios G Coutsolelos
Hydrogen evolution using photocatalytic systems based on artificial photosynthesis is a major approach toward solar energy conversion and storage. In the polyoxometalate-based photocatalytic systems proposed in the past, middle/near UV light irradiation and noble-metal catalysts were mainly used. Although recently polyoxometalates were sensitized in visible light, photosensitizers or catalysts based on noble metals, and/or poor activity of polyoxometalates were generally obtained. Here we show the highly efficient [turnover number (TON)=215] hydrogen evolution induced by the zinc(II) mesotetrakis(N-methyl-pyridinium-4-yl)porphyrin (ZnTMPyP(4+) ) sensitization of a series of polyoxometalate catalysts (two Dawson type, P2 Mo18 O62(6-) and P2 W18 O62(6-) anions, and one Keplerate {Mo132 } cluster) in a visible-light-driven, noble-metal-free, and fully water-soluble system...
October 24, 2016: ChemSusChem
Srikanth Dasari, Swati Singh, Sri Sivakumar, Ashis K Patra
Dual-photosensitized stable Eu(ΙΙΙ) and Tb(ΙΙΙ) complexes, namely [Eu(dpq)(tfnb)3 ] (1) and [Tb(dpq)(tfnb)3 ] (2), in which dpq=dipyrido[3,2-d:2',3'-f]quinoxaline and Htfnb=4,4,4-trifluoro-1-(2-napthyl)-1,3-butanedione, were designed as bioimaging and light-responsive therapeutic agents. Their X-ray structures, photophysical properties, biological interactions, photoinduced DNA damage, photocytotoxicity, and cellular uptake properties were studied. Discrete mononuclear complexes adopt an eight-coordinated {LnN2 O6 } distorted square antiprism geometry with bidentate N,N-donor dpq and O,O-donor tfnb ligands...
October 24, 2016: Chemistry: a European Journal
Hao Wu, Fang Zeng, Hang Zhang, Jiangsheng Xu, Jianrong Qiu, Shuizhu Wu
The applications of photodynamic therapy (PDT) are usually limited by photosensitizers' side effects and singlet oxygen's short half-life. Herein, a mitochondria-targeted nanosystem is demonstrated to enhance the PDT efficacy by releasing a bio-precursor of photosensitizer under two-photon irradiation. A phototriggerable coumarin derivative is first synthesized by linking 5-aminolevulinic acid (5-ALA, the bio-precursor) to coumarin; and the nanosystem (CD-ALA-TPP) is then fabricated by covalently incorporating this coumarin derivative and a mitochondria-targeting compound triphenylphosphonium (TPP) onto carbon dots (CDs)...
February 2016: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
Liping Zhang, Ping Cui, Hongbin Yang, Jiazang Chen, Fangxing Xiao, Yuanyuan Guo, Ye Liu, Weina Zhang, Fengwei Huo, Bin Liu
Ti-based metal-organic frameworks (MOFs) are demonstrated as promising photosensitizers for photoelectrochemical (PEC) water splitting. Photocurrents of TiO2 nano wire photoelectrodes can be improved under visible light through sensitization with aminated Ti-based MOFs. As a host, other sensitizers or catalysts such as Au nanoparticles can be incorporated into the MOF layer thus further improving the PEC water splitting efficiency.
January 2016: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
Michelle Maclean, John G Anderson, Scott J MacGregor, Tracy White, Chintamani D Atreya
Bacterial contamination of injectable stored biological fluids such as blood plasma and platelet concentrates preserved in plasma at room temperature is a major health risk. Current pathogen reduction technologies (PRT) rely on the use of chemicals and/or ultraviolet light, which affects product quality and can be associated with adverse events in recipients. 405 nm violet-blue light is antibacterial without the use of photosensitizers and can be applied at levels safe for human exposure, making it of potential interest for decontamination of biological fluids such as plasma...
2016: Journal of Blood Transfusion
Boris Pinchuk, Thorsten von Drathen, Viktoria Opel, Christian Peifer
Dabrafenib (Tafinlar) was approved in 2013 by the FDA as a selective single agent treatment for patients with BRAF(V600E) mutation-positive advanced melanoma. One year later, a combination of dabrafenib and trametinib was used for treatment of BRAF(V600E/K) mutant metastatic melanoma. In the present study, we report on hitherto not described photosensitivity of dabrafenib both in organic and aqueous media. The half-lives for dabrafenib degradation were determined. Moreover, we revealed photoinduced chemical conversion of dabrafenib to its planar fluorescent derivative dabrafenib_photo 2...
October 13, 2016: ACS Medicinal Chemistry Letters
A P Cádiz Bedini, S Muthmann, J Allgaier, K Bittkau, F Finger, R Carius
We report on a liquid hydridosilane precursor ink prepared via the ultrasonically induced ring-opening polymerisation of cyclopentasilane (Si5H10) without irradiation by ultraviolet light. The sonication is carried out in N2 atmosphere at temperatures between 20 and 75°C. We use size exclusion chromatography (SEC) to show polymer growth and estimate molecular mass with increasing sonication time. In combination with UV-vis transmission measurements, further SEC analysis is used to compare solutions subjected to either purely thermal or ultrasonic treatment at the same process temperature and for the same duration...
January 2017: Ultrasonics Sonochemistry
Guorui Jin, Jun Li, Kai Li
Photosensitive semiconducting polymer (SP) combined with light stimulation has shown the capability in promoting the proliferation of human dermal fibroblasts (HDFs). However, the high cytotoxicity of the used SP hindered its further application in bioactive scaffolds. In this contribution, we designed and synthesized a SP, poly (N,N-bis(2-octyldodecyl)-3,6-di(thiophen-2-yl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione-alt-thieno[3,2-b]thiophene) (PDBTT) with low cytotoxicity and strong absorbance in red and near-infrared region (600-1200nm)...
January 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
A N Severyukhina, N V Petrova, A M Yashchenok, D N Bratashov, K Smuda, I A Mamonova, N A Yurasov, D M Puchinyan, R Georgieva, H Bäumler, A Lapanje, D A Gorin
Increasing antimicrobial resistance requires the development of novel materials and approaches for treatment of various infections. Utilization of photodynamic therapy represents an advanced alternative to antibiotics and metal-based agents. Here, we report the fabrication of electrospun material that possesses benefits of both topical antimicrobial and photodynamic therapies. This material combines chitosan, as a biocompatible polymer, and a second generation photosensitizer. The incorporation of photosensitizer doesn't affect the material morphology and its nearly uniform distribution in fibers structure was observed by confocal Raman microscopy...
January 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
Milene N O Moritz, Joyce L S Gonçalves, Irwin A P Linares, Janice R Perussi, Kleber T de Oliveira
An amphiphilic chlorin derivative (CHL-T) was prepared from methylpheophorbide a (CHL) and 2-Amino-2-(hydroxymethyl)-1,3-propanediol (TRISMA(®)). The new chlorin was compared to other dyes (CHL and Hypericin) in relation to photophysical and photobiological activities in tumor and non-tumor cell lines. Cytotoxicity and cell death target were determined to evaluate the CHL-T efficiency, comparing to the precursor CHL and to the well-known dye hypericin (HY). All of the studied compounds exhibited absorption bands in the therapeutic window and presented a small fluorescence quantum yield compared to the reference dye (rhodamine B)...
October 18, 2016: Photodiagnosis and Photodynamic Therapy
Aurélie Stallivieri, Ludovic Colombeau, Gulim Jetpisbayeva, Albert Moussaron, Bauyrzhan Myrzakhmetov, Philippe Arnoux, Samir Acherar, Régis Vanderesse, Céline Frochot
Recent researches in photodynamic therapy have focused on novel techniques to enhance tumour targeting of anticancer drugs and photosensitizers. Coupling a photosensitizer with folic acid could allow more effective targeting of folate receptors which are over-expressed on the surface of many tumour cells. In this study, different folic acid-OEG-conjugated photosensitizers were synthesized, characterized and their photophysical properties were evaluated. The introduction of an OEG does not significantly improve the hydrophilicity of the FA-porphyrin...
October 10, 2016: Bioorganic & Medicinal Chemistry
Troy A Skwor, Stephanie Klemm, Hanyu Zhang, Brianna Schardt, Stephanie Blaszczyk, Matthew A Bork
Increasing rates of antibiotic resistance coupled with the lack of novel antibiotics threatens proper clinical treatment and jeopardizes their use in prevention. A photodynamic approach appears to be an innovative treatment option, even for multi-drug resistant strains of bacteria. Three components are utilized in photodynamic inactivation: a photosensitizer, light source, and oxygen. Variations in photosensitizers strongly influence microbial binding and bactericidal activity. In this study, four different cationic metalloporphyrins (Cu(2+), Fe(2+), Pd(2+), Zn(2+)) were compared to the free-base ligand 5,10,15,20-tetrakis(N-methylpyridinium-4-yl)porphyrin regarding their electronic properties and generation of reactive oxygen species upon subsequent 405nm violet-blue irradiation...
October 15, 2016: Journal of Photochemistry and Photobiology. B, Biology
Martin Heberle, Stefanie Tschierlei, Nils Rockstroh, Mark Ringenberg, Wolfgang Frey, Henrik Junge, Matthias Beller, Stefan Lochbrunner, Michael Karnahl
A series of heteroleptic copper(I) photosensitizers of the type [(P^P)Cu(N^N)]+ with an extended π-system in the backbone of the diimine ligand have been prepared. The structures of all complexes are completely characterized by NMR spectroscopy, mass spectrometry and X-ray crystallography. These novel photosensitizers were assessed with respect to the photocatalytic reduction of protons in the presence of triethylamine and [Fe3(CO)12]. While the solid state structures and computational results show no significant impact of the π-extension on the structural properties decreased activities were observed...
October 21, 2016: Chemistry: a European Journal
Juliana Marioni, María Angel da Silva, José Luis Cabrera, Susana C Núñez Montoya, María Gabriela Paraje
BACKGROUND: Candida tropicalis is increasingly becoming among the most commonly isolated pathogens causing fungal infections with an important biofilm-forming capacity. PURPOSE: This study addresses the antifungal effect of rubiadin (AQ1) and rubiadin 1-methyl ether (AQ2), two photosensitizing anthraquinones (AQs) isolated from Heterophyllaea pustulata, against C. tropicalis biofilms, by studying the cellular stress and antioxidant response in two experimental conditions: darkness and irradiation...
November 15, 2016: Phytomedicine: International Journal of Phytotherapy and Phytopharmacology
Takayo Miyakogawa, Genta Kanai, Ryoko Tatsumi, Hiroo Takahashi, Kaichiro Sawada, Takatoshi Kakuta, Masafumi Fukagawa
BACKGROUND: Feasibility of photodynamic therapy (PDT) for secondary hyperparathyroidism (SHPT) was examined in a rat model of SHPT. METHODS: A photosensitizer, 5-aminolevulinic acid (5-ALA), was injected intraperitoneally, and the parathyroid glands were irradiated either after surgical exposure with 385-nm light or transdermally with 630-nm light from a light-emitting diode (LED) lamp. RESULTS: PDT with high 5-ALA and irradiation doses caused severe hypoparathyroidism in SHPT rats within two days...
October 18, 2016: Clinical and Experimental Nephrology
Sujita Kumar Kar
Melasma is a hyperpigmented dermatological condition common in females. Drugs such as steroids, cosmetics, and photosensitizing agents are known to cause melasma. We report here a case of an adult male with obsessive-compulsive disorder, receiving clomipramine, who developed melasma.
July 2016: Indian Journal of Pharmacology
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