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Gold nanoparticles radiation

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https://www.readbyqxmd.com/read/28806685/ecofriendly-gold-nanoparticles-lysozyme-interaction-thermodynamical-perspectives
#1
Swarup Roy, Shailendra K Saxena, Suryakant Mishra, Priyanka Yogi, P R Sagdeo, Rajesh Kumar
In the featured work interaction between biosynthesized gold nanoparticles (GNP) and lysozyme (Lys) has been studied using multi-spectroscopic approach. A moderate association constant (Kapp) of 2.66×10(4)L/mol has been observed indicative of interactive nature. The binding constant (Kb) was 1.99, 6.30 and 31.6×10(4)L/mol at 291, 298 and 305K respectively and the number of binding sites (n) was found to be approximately one. Estimated values of thermodynamic parameters (Enthalpy change, ΔH=141.99kJ/mol, entropy change, ΔS=570J/mol/K, Gibbs free energy change, ΔG=-27...
August 8, 2017: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/28799676/morphology-visualization-of-irregular-shape-bacteria-by-electron-holography-and-tomography
#2
Eduardo Ortega, Jesús Cantu-Valle, Germán Plascencia-Villa, Sandra Vergara, Fernando Mendoza-Santoyo, Alejandra Londono-Calderon, Ulises Santiago, Arturo Ponce
In the current work, irregular morphology of Staphylococcus aureus bacteria has been visualized by phase retrieval employing off-axis electron holography (EH) and 3D reconstruction electron tomography using high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM). Bacteria interacting with gold nanoparticles (AuNP) acquired a shrunken or irregular shape due to air dehydration processing. STEM imaging shows the attachment of AuNP on the surface of cells and suggests an irregular 3D morphology of the specimen...
August 11, 2017: Microscopy Research and Technique
https://www.readbyqxmd.com/read/28799495/a-nanotechnology-based-strategy-to-increase-the-efficiency-of-cancer-diagnosis-and-therapy-folate-conjugated-gold-nanoparticles
#3
Jaber Beik, Sara Khademi, Neda Attaran, Saeed Sarkar, Ali Shakeri-Zadeh, Habib Ghaznavi, Hossein Ghadiri
BACKGROUND: Gold nanoparticle (AuNP), owing to its elegant physicochemical properties, has been recently introduced as a promising theranostic nanoparticle. Folic acid is a necessary vitamin for cell proliferation and cancer cells highly require such an essential molecule to be replicated. Accordingly, surface functionalization of AuNP with folic acid may offer great potentials for development of a new nanotechnology based strategy to increase the efficiency of cancer diagnosis and therapy...
August 10, 2017: Current Medicinal Chemistry
https://www.readbyqxmd.com/read/28795273/capacity-of-gold-nanoparticles-in-cancer-radiotherapy
#4
REVIEW
Nadeem M S Nagi, Yasir A M Khair, Ahmed M E Abdalla
Radiotherapy is the ionizing radiation used for treatment of cancer and other diseases. Although radiotherapy is the major treatment for cancer, a lot of patients do not undergo radiation due to associated risks such as radiation pneumonitis, cardiovascular complications, development of secondary tumor, and lymphedema. However, the advantages of nanotechnology provide a unique potential to enhance radiotherapeutic performance, in particular by utilizing gold nanoparticles (Au NPs). In this review, we briefly describe the current direction of research towards the use of Au NPs for radiotherapeutic enhancement, combination, monitoring and in side effect reductions...
August 9, 2017: Japanese Journal of Radiology
https://www.readbyqxmd.com/read/28778062/dna-aptamer-functionalized-gold-nanostructures-for-molecular-recognition-and-photothermal-inactivation-of-methicillin-resistant-staphylococcus-aureus
#5
Ismail Ocsoy, Sadi Yusufbeyoglu, Vedat Yılmaz, Eric S McLamore, Nilay Ildız, Ahmet Ülgen
In this work, we report the development of DNA aptamer-functionalized gold nanoparticles (Apt@Au NPs) and gold nanorods (Apt@Au NRs) for inactivation of Methicillin-resistant Staphylococcus aureus (MRSA) with targeted photothermal therapy (PTT). Although both Apt@Au NPs and Apt@Au NRs specifically bind to MRSA cells, Apt@Au NPs and Apt@Au NRs inactivated ∼5% and over 95% of the cells,respectively through PTT. This difference in inactivation was based on the relatively high longitudinal absorption of near-infrared (NIR) radiation and strong photothermal conversion capability for the Apt@Au NRs compared to the Apt@Au NPs...
July 25, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28777315/spectral-selectivity-of-plasmonic-interactions-between-individual-up-converting-nanocrystals-and-spherical-gold-nanoparticles
#6
Dawid Piątkowski, Mikołaj K Schmidt, Magdalena Twardowska, Marcin Nyk, Javier Aizpurua, Sebastian Maćkowski
We experimentally demonstrate strong spectral selectivity of plasmonic interaction that occurs between α-NaYF₄:Er(3+)/Yb(3+) nanocrystals, which feature two emission bands, and spherical gold nanoparticles, with plasmon frequency resonant with one of the emission bands. Spatially-resolved luminescence intensity maps acquired for individual nanocrystals, together with microsecond luminescence lifetime images, show two qualitatively different effects that result from the coupling between plasmon excitations in metallic nanoparticles and emitting states of the nanocrystals...
August 4, 2017: Materials
https://www.readbyqxmd.com/read/28763763/fluorescence-enhancement-via-varied-long-chain-thiol-stabilized-gold-nanoparticles-a-study-of-far-field-effect
#7
Jayasmita Jana, Teresa Aditya, Mainak Ganguly, Shyamal Kumar Mehetor, Tarasankar Pal
Metal enhanced fluorescence of carbon dots has been reported in aqueous solution. Moderately fluorescing carbon dots (λex=360nm and λem=440nm) of 6-8nm diameters (CDA) have been synthesized from freshly prepared aqueous ascorbic acid solution under modified hydrothermal treatment. The CDA fluorescence is quenched at the close proximity with gold nanoparticles (AuNPs). Here, a substrate specific near-field electric field distribution is pronounced. Anticipating distance dependent fluorescence enhancement phenomenon, long-chain aliphatic thiol capped AuNPs are introduced to improve fluorescence of moderately fluorescing CDAs...
July 24, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28762334/controlled-formation-of-gold-nanostructures-on-biopolymer-films-upon-electromagnetic-radiation
#8
Andrea Mescola, Claudio Canale, Despina Fragouli, Athanassia Athanassiou
The localized formation of gold nanostructures with controlled size and shape on chitosan films doped with gold precursor upon electromagnetic irradiation of various types is here demonstrated. Such controlled formation is achieved by tuning the wavelength, the energy and the interaction time of the radiation with the composite films. In particular, the use of a single UV nanosecond laser pulse results in the formation of gold sub-micron platelets with specific crystal structure, while increasing the number of pulses, further precursor reduction and photofragmentation induce the formation of gold nanoparticles...
August 1, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28752783/reactive-oxygen-species-based-measurement-of-the-dependence-of-the-coulomb-nanoradiator-effect-on-proton-energy-and-atomic-z-value
#9
Seung-Jun Seo, Jae-Kun Jeon, Sung-Mi Han, Jong-Ki Kim
PURPOSE: The Coulomb nanoradiator (CNR) effect produces the dose enhancement effects from high-Z nanoparticles under irradiation with a high-energy ion beam. To gain insight into the radiation dose and biological significance of the CNR effect, the enhancement of reactive oxygen species (ROS) production from iron oxide or gold NPs (IONs or AuNPs, respectively) in water was investigated using traversing proton beams. METHODS AND MATERIALS: The dependence of nanoradiator-enhanced ROS production on the atomic Z value and proton energy was investigated...
July 28, 2017: International Journal of Radiation Biology
https://www.readbyqxmd.com/read/28727443/plasmonic-thermal-decomposition-digestion-of-proteins-a-rapid-on-surface-protein-digestion-technique-for-mass-spectrometry-imaging
#10
Rong Zhou, Franco Basile
A method based on plasmon surface resonance absorption and heating was developed to perform a rapid on-surface protein thermal decomposition and digestion suitable for imaging MS and/or profiling. This photo-thermal process or plasmonic thermal decomposition/digestion (plasmonic-TDD) method incorporates a continuous wave (CW) laser excitation and gold nanoparticles (Au-NPs) to induce known thermal decomposition reactions that cleave peptides and proteins specifically at the C-terminus of aspartic acid and at the N-terminus of cysteine...
July 20, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28687649/imposed-environmental-stresses-facilitate-cell-free-nanoparticle-formation-by-deinococcus-radiodurans
#11
Angela Chen, Lydia M Contreras, Benjamin K Keitz
The biological synthesis of metal nanoparticles has been examined in a wide range of organisms due to increased interest in green synthesis and environmental remediation applications involving heavy metal ion contamination. Deinococcus radiodurans is particularly attractive for environmental remediation involving metal reduction due to its high resistance to radiation and other environmental stresses. However, few studies have thoroughly examined the relationship between environmental stresses and their resulting effect on nanoparticle biosynthesis...
July 7, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28666767/towards-breast-cancer-rotational-radiotherapy-with-synchrotron-radiation
#12
Francesca Di Lillo, Giovanni Mettivier, Antonio Sarno, Roberta Castriconi, Paolo Russo
PURPOSE: We performed the first investigations, via measurements and Monte Carlo simulations on phantoms, of the feasibility of a new technique for synchrotron radiation rotational radiotherapy for breast cancer (SR(3)T). METHODS: A Monte Carlo (MC) code based on Geant4 toolkit was developed in order to simulate the irradiation with the SR(3)T technique and to evaluate the skin sparing effect in terms of centre-to-periphery dose ratio at different energies in the range 60-175keV...
June 27, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28661675/hot-carrier-mediated-photon-upconversion-in-metal-decorated-quantum-wells
#13
Gururaj V Naik, Alex J Welch, Justin A Briggs, Michelle L Solomon, Jennifer A Dionne
Manipulating the frequency of electromagnetic waves forms the core of many modern technologies, ranging from imaging and spectroscopy to radio and optical communication. The process of converting photons from higher to lower energy is easily accomplished and technologically widespread. However, upconversion, which is the process of converting lower-energy photons into higher-energy photons, is still a growing field of study with nascent applications and burgeoning interest. Here, we experimentally demonstrate a new photon upconversion technique mediated by hot carriers in plasmonic nanostructures...
July 3, 2017: Nano Letters
https://www.readbyqxmd.com/read/28654384/fluorescent-plasmonic-and-radiotherapeutic-properties-of-the-177-lu-dendrimer-aunp-folate-bombesin-nanoprobe-located-inside-cancer-cells
#14
Héctor Mendoza-Nava, Guillermina Ferro-Flores, Flor de María Ramírez, Blanca Ocampo-García, Clara Santos-Cuevas, Erika Azorín-Vega, Nallely Jiménez-Mancilla, Myrna Luna-Gutiérrez, Keila Isaac-Olivé
The integration of fluorescence and plasmonic properties into one molecule is of importance in developing multifunctional imaging and therapy nanoprobes. The aim of this research was to evaluate the fluorescent properties and the plasmonic-photothermal, therapeutic, and radiotherapeutic potential of (177)Lu-dendrimer conjugated to folate and bombesin with gold nanoparticles in the dendritic cavity ((177)Lu-DenAuNP-folate-bombesin) when it is internalized in T47D breast cancer cells. The intense near-Infrared (NIR) fluorescence emitted at 825 nm from the conjugate inside cells corroborated the usefulness of DenAuNP-folate-bombesin for optical imaging...
January 1, 2017: Molecular Imaging
https://www.readbyqxmd.com/read/28595565/gold-nanoparticles-by-laser-ablation-for-x-ray-imaging-and-protontherapy-improvements
#15
Torrisi Lorenzo, Nancy Restuccia, Irene Paterniti
Gold nanoparticles, 5-20 nm in diameter, were generated with a pulsed Nd:YAG laser at 1010 W/cm2 at solution concentrations ranging between 1-100 mg/ml. Nanoparticles were characterized using optical absorbance, X-ray fluorescence, SEM, and TEM. Biocompatible nanoparticle solutions were injected by intravenously into the tail veins of mice followed by X-ray imaging using 20-45 keV photons to evaluate the uptake and the clearance by different organs of the nanoparticles. The incremental X-ray contrast imaging using gold nanoparticles was investigated and measured...
June 8, 2017: Recent Patents on Nanotechnology
https://www.readbyqxmd.com/read/28585277/technical-note-monte-carlo-calculations-of-the-aapm-tg-43-brachytherapy-dosimetry-parameters-for-a-new-titanium-encapsulated-yb-169-source
#16
Francisco J Reynoso, John J Munro Iii, Sang Hyun Cho
Due to a number of distinct advantages resulting from the relatively low energy gamma ray spectrum of Yb-169, various designs of Yb-169 sources have been developed over the years for brachytherapy applications. Lately, Yb-169 has also been suggested as an effective and practical radioisotope option for a novel radiation treatment approach often known as gold nanoparticle-aided radiation therapy (GNRT). In a recently published study, the current investigators used the Monte Carlo N-Particle Version 5 (MCNP5) code to design a novel titanium-encapsulated Yb-169 source optimized for GNRT applications...
June 6, 2017: Journal of Applied Clinical Medical Physics
https://www.readbyqxmd.com/read/28581292/photoinitiated-dynamics-in-amorphous-solid-water-via-nanoimprint-lithography
#17
Christopher Larson, Yuanrui Li, Wei Wu, Hanna Reisler, Curt Wittig
Laser pulses that act on fragile samples often alter them irreversibly, motivating single-pulse data collection. Amorphous solid water (ASW) is a good example. In addition, neither well-defined paths for molecules to travel through ASW nor sufficiently small samples to enable molecular dynamics modeling have been achieved. Combining nanoimprint lithography and photoinitiation overcomes these obstacles. An array of gold nanoparticles absorbs pulsed (10 ns) 532 nm radiation and converts it to heat, and doped ASW films grown at about 100 K are ejected from atop the irradiated nanoparticles into vacuum...
June 21, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28557630/the-exploitation-of-low-energy-electrons-in-cancer-treatment
#18
Mohammad Rezaee, Richard P Hill, David A Jaffray
Given the distinct characteristics of low-energy electrons (LEEs), particularly at energies less than 30 eV, they can be applied to a wide range of therapeutic modalities to improve cancer treatment. LEEs have been shown to efficiently produce complex molecular damage resulting in substantial cellular toxicities. Since LEEs are produced in copious amounts from high-energy radiation beam, including photons, protons and ions; the control of LEE distribution can potentially enhance the therapeutic radio of such beams...
August 2017: Radiation Research
https://www.readbyqxmd.com/read/28543610/metallic-nanoparticles-irradiated-by-low-energy-protons-for-radiation-therapy-are-there-significant-physical-effects-to-enhance-the-dose-delivery
#19
Anne-Catherine Heuskin, Bernard Gallez, Olivier Feron, Philippe Martinive, Carine Michiels, Stéphane Lucas
PURPOSE: To identify which physical properties of nanoparticles are correlated with the survival fraction of cells exposed in vitro to low-energy protons in combination with nanoparticles. METHODS: The Geant4 simulation toolkit (version 10.3) was used to model nanoparticles of different sizes (5-50 nm) and materials (Ti, Zr, Hf, Ta, Au, Pt), with or without an organic capping ensuring biocompatibility and to irradiate them with 1.3 or 4 MeV protons and 5.3 MeV alpha particles...
August 2017: Medical Physics
https://www.readbyqxmd.com/read/28520555/relaxation-lifetimes-of-plasmonically-enhanced-hybrid-gold-carbon-nanotubes-systems
#20
Mareen Gläske, Manoj Kumar, Timo Bißwanger, Saulius Vaitiekenas, Cesare Soci, Rohit Narula, Annalisa Bruno, Antonio Setaro
Recently, we introduced a novel hybridization route for carbon nanotubes using gold nanoparticles, whose close proximity neatly enhances their radiative emission. Here we investigate the mechanisms behind the enhancement by monitoring the de-excitation dynamics of our π-hybrids through two-color pump-probe time-resolved spectroscopy. The de-excitation process reveals a fast component and a slow component. We find that the presence of gold prominently affects the fast processes, indicating a stronger influence of the gold nanoparticle on the intra-band non-radiative relaxation than on the inter-band recombination of the SWNT...
May 18, 2017: Nanotechnology
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