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Gold nanoparticles radiation

Seon Namgung, Daniel A Mohr, Daehan Yoo, Palash Bharadwaj, Steven J Koester, Sang-Hyun Oh
Metal nanoparticles that can couple light into tightly confined surface plasmons bridge the size mismatch between the wavelength of light and nanostructures are one of the smallest building blocks of nano-optics. However, plasmonic nanoparticles have been primarily studied to concentrate or scatter incident light as an ultrasmall antenna, while studies of their intrinsic plasmonic light emission properties have been limited. Although light emission from plasmonic structures can be achieved by inelastic electron tunneling, this strategy cannot easily be applied to isolated single nanoparticles due to the difficulty in making electrical connections without disrupting the particle plasmon mode...
March 2, 2018: ACS Nano
Xiaoyang Du, Xiaoxia Zhang, Chunlai Jiang, Weilu Zhang, Lizhu Yang
A novel fluorescence sensor of NR-β-CD@AuNPs was prepared for the trace detection of nitrite in quantities as low as 4.25 × 10-3 μg∙mL-1 in an aqueous medium. The fluorescence was due to the host-guest inclusion complexes between neutral red (NR) molecules and gold nanoparticles (AuNPs), which were modified by per-6-mercapto-beta-cyclodextrins (SH-β-CDs) as both a reducing agent and a stabilizer under microwave radiation. The color of the NR-β-CD@AuNPs changed in the presence of nitrite ions. A sensor was applied to the determination of trace nitrites in environmental water samples with satisfactory results...
February 25, 2018: Sensors
Hasan Norouzi, Karim Khoshgard, Fatemeh Akbarzadeh
Hyperthermia is an anti-cancer treatment in which the temperature of the malignant tumor is increased more than other adjacent normal tissues. Microwave, ultrasound, laser, and radiofrequency sources have been used for hyperthermia of cancerous tissues. In the past decade, near-infrared (NIR) laser for cancer therapy, known as photo-thermal therapy (PTT), was expanded in which the photo-sensitizer agent converts the light photon energy to heat. The heat following PTT can destroy cancer cells. There are some photo-sensitizer agents which have been used for PTT; however, owing to recent advances in nanotechnology, noble metal nanoparticles like gold (Au) nanoparticles (GNPs) have been used successfully in PTT...
February 28, 2018: Lasers in Medical Science
Sherif M Gadoue, Piotr Zygmanski, Erno Sajo
AIM: In nanoparticle-aided radiotherapy, the computational paradigm has been that inside the cell, nanoparticles are distributed sparsely and solitarily. However, experiments reveal significant cluster formation, which affects radiosensitization and must be considered in clinical treatment planning. We characterize the impact of gold nanoparticle agglomeration on the predicted radiation dose enhancement as function of size, geometry, morphology and incident beam energy. MATERIALS & METHODS: Next-generation coupled electron-photon deterministic computations were performed using subnanometric unstructured spatial mesh...
February 27, 2018: Nanomedicine
Sara Khademi, Saeed Sarkar, Sharmin Kharrazi, Seyed Mohammad Amini, Ali Shakeri-Zadeh, Mohammad Reza Ay, Hossein Ghadiri
Increasing attention has been focused on the use of nanostructures as contrast enhancement agents in medical imaging, especially in computed tomography (CT). To date, gold nanoparticles (GNPs) have been demonstrated to have great potential as contrast agents for CT imaging. This study was designed to evaluate any effect on X-ray attenuation that might result from employing GNPs with a variety of shapes, sizes, surface chemistries, and concentrations. Gold nanorods (GNRs) and spherical GNPs were synthesized for this application...
January 2018: Physica Medica: PM
Daniel Coluccia, Carlyn A Figueiredo, Megan YiJun Wu, Alexandra N Riemenschneider, Roberto Diaz, Amanda Luck, Christian Smith, Sunit Das, Cameron Ackerley, Meaghan O'Reilly, Kullervo Hynynen, James T Rutka
Glioblastoma (GBM) is the most common and aggressive primary brain tumor resulting in high rates of morbidity and mortality. A strategy to increase the efficacy of available drugs and enhance the delivery of chemotherapeutics through the blood brain barrier (BBB) is desperately needed. We investigated the potential of Cisplatin conjugated gold nanoparticles (GNP-UP-Cis) in combination with MR-guided Focused Ultrasound (MRgFUS) to intensify GBM treatment. Viability assays demonstrated that GNP-UP-Cis greatly inhibits the growth of GBM cells compared to free cisplatin and shows marked synergy with radiation therapy...
February 19, 2018: Nanomedicine: Nanotechnology, Biology, and Medicine
Chengxu Cai, Mingzhe Wang, Liming Wang, Bing Wang, Weiyue Feng, Chunying Chen
Characterization of bio-nano interface is crucial for developing safer and more efficient nanoparticles in nanomedical application. PEGylation is commonly used in nanocarrier for drug delivery, as it confers nanoparticles good stability, stealth effect and better targeting specificity compared with those without PEGylation. However, the protein binding state on PEGylated AuNP is still limited known. In present work, we prepared 13 nm AuNPs and then PEGylated them with thiol PEG methoxy. Lysozyme is selected as a model protein and to investigate the interactions on protein-PEGylated/AuNP interface...
August 1, 2018: Journal of Nanoscience and Nanotechnology
L Coelho, I F Almeida, J M Sousa Lobo, J P Sousa E Silva
PURPOSE: Several active compounds are sensitive to light, especially to the ultraviolet radiation (UV-R) leading to their degradation or modification, with lost or decrease of their biological activity. The aim of this study was to perform a systematic review regarding photostabilization strategies used on health products and perform a critical appraisal of their effectiveness. RESULTS: The bibliographic search identified 2261 results and merely 40 studies met the selection criteria...
February 10, 2018: International Journal of Pharmaceutics
Christopher J Russo, Richard Henderson
The fluctuating granularity or "bee swarm" effect seen in highly defocussed transmission electron micrographs is caused by microscopic charge fluctuations in the specimen created by the illuminating beam. In the field of high-resolution single particle electron cryomicroscopy (cryoEM), there has been a concern that this fluctuating charge might cause defocus-dependent Thon ring fading which would degrade the final image. In this paper, we have analysed the 2.35 Å fringes from the (111) reflection in images of gold nanoparticles embedded in amorphous ice...
January 31, 2018: Ultramicroscopy
Ali Neshastehriz, Maziar Khateri, Habib Ghaznavi, Ali Shakeri-Zadeh
BACKGROUND AND PURPOSE: It has been well-known both gold nanoparticles (AuNPs) and cisplatin are potential radiosensitizers for radiotherapy of cancer. In this in vitro study, we investigated the chemo-radiotherapeutic effects of alginate nanogel co-loaded with AuNPs and cisplatin (ACA) on U87-MG human glioblastoma cells. METHODS: Based on the accomplished pilot studies, U87-MG cells were incubated with ACA and cisplatin at 10% inhibitory concentration (IC10) for 4 h...
January 30, 2018: Anti-cancer Agents in Medicinal Chemistry
Hongbo Zhang, Yueqi Zhu, Liangliang Qu, Huayin Wu, Haixin Kong, Zhou Yang, Dong Chen, Ermei Makila, Jarno J Salonen, Hélder A Santos, Mingtan Hai, David A Weitz
Porous silicon nanoparticles (PSiNPs) and gold nanorods (AuNRs) can be used as biocompatible nanocarriers for delivery of therapeutics, but undesired leakage makes them inefficient. By encapsulating the PSiNPs and AuNRs in a hydrogel shell, we create a biocompatible functional nanocarrier that enables sustained release of therapeutics. Here, we report the fabrication of AuNRs conjugated PSi nanoparticles (AuNRsPSiNPs) through two-steps chemical reaction for high-capacity loading of hydrophobic and hydrophilic therapeutics with photothermal property...
January 31, 2018: Nano Letters
Eun Ho Kim, Mi-Sook Kim, Hyo Sook Song, Seung Hoon Yoo, Sei Sai, Kwangzoo Chung, Jiwon Sung, Youn Kyoung Jeong, YunHui Jo, Myonggeun Yoon
The purpose of this study was to investigate the potential of gold nanoparticles as radiosensitizer for use in neutron therapy against hepatocellular carcinoma. The hepatocellular carcinoma cells lines Huh7 and HepG2 were irradiated with γ and neutron radiation in the presence or absence of gold nanoparticles. Effects were evaluated by transmission electron microscopy, cell survival, cell cycle, DNA damage, migration, and invasiveness. Gold nanoparticles significantly enhanced the radiosensitivity of Huh7 and HepG2 cells to γ-rays by 1...
December 22, 2017: Oncotarget
Sahil Inamdar, Karthik Pushpavanam, Jarrod Lentz, Martin Bues, Aman Anand, Kaushal Rege
Proton beam therapy (PBT) is a state-of-the-art radiotherapy treatment approach that uses focused proton beams for tumor ablation.[1] A key advantage of this approach over conventional photon radiotherapy (XRT) is the unique dose deposition characteristics of protons, resulting in superior healthy tissue sparing. This results in fewer unwanted side effects and improved outcomes for patients. Current available dosimeters are intrinsic, complex and expensive; hence cannot be used to determine the dose delivered to the tumor routinely...
January 5, 2018: ACS Applied Materials & Interfaces
Surong Zhang, Suresh Gupta, Thomas J Fitzgerald, Alexei A Bogdanov
Constitutively activated signal transducer and activator of transcription 3 (STAT3) factor is an important therapeutic target in head and neck cancer (HNC). Despite early promising results, a reliable systemic delivery system for STAT3- targeted oligonucleotide (ODN) drugs is still needed for future clinical translation of anti-STAT3 therapies. We engineered and tested a novel ODN duplex/gold nanoparticle (AuNP)-based system carrying a therapeutic STAT3 decoy (STAT3d) payload. This strategy is two-pronged because of the additive STAT3 antagonism and radiosensitizing properties of AuNP...
2018: Nanotheranostics
Allison M Khoo, Sang Hyun Cho, Francisco J Reynoso, Maureen Aliru, Kathryn Aziz, Monica Bodd, Xi Yang, Md F Ahmed, Selcuk Yasar, Nivedh Manohar, Jongmin Cho, Ramesh Tailor, Howard D Thames, Sunil Krishnan
Theoretical investigations suggest that gold nanoparticle (GNP)-mediated radiation dose enhancement and radiosensitization can be maximized when photons interact with gold, predominantly via photoelectric absorption. This makes ytterbium (Yb)-169, which emits photons with an average energy of 93 keV (just above the K-edge of gold), an ideal radioisotope for such purposes. This investigation tests the feasibility of tumor-specific prostate brachytherapy achievable with Yb-169 and actively targeted GNPs, using an external beam surrogate of Yb-169 created from an exotic filter material - erbium (Er) and a standard copper-filtered 250 kVp beam...
December 22, 2017: Scientific Reports
Jaber Beik, Maryam Jafariyan, Alireza Montazerabadi, Ali Ghadimi-Daresajini, Parastoo Tarighi, Alireza Mahmoudabadi, Habib Ghaznavi, Ali Shakeri-Zadeh
X-ray computed tomography (CT) requires an optimal compromise between image quality and patient dose. While high image quality is an important requirement in CT, the radiation dose must be kept minimal to protect the patients from ionizing radiation-associated risks. The use of probes based on gold nanoparticles (AuNPs) along with active targeting ligands for specific recognition of cancer cells may be one of the balanced solutions. Herein, we report the effect of folic acid (FA)-modified AuNP as a targeted nanoprobe on the contrast enhancement of CT images as well as its potential for patient dose reduction...
December 12, 2017: Artificial Cells, Nanomedicine, and Biotechnology
Stuti Bhagat, N V Srikanth Vallabani, Vaithiyalingam Shutthanandan, Mark Bowden, Ajay S Karakoti, Sanjay Singh
Catalytically active individual gold (Au) and cerium oxide (CeO2 ) nanoparticles (NPs) are well known to exhibit specific enzyme-like activities, such as natural catalase, oxidase, superoxide dismutase, and peroxidase enzymes. These activities have been maneuvered to design several biological applications such as immunoassays, glucose detection, radiation and free radical protection and tissue engineering. In biological systems, multienzyme complexes are involved in catalyzing important reactions of essential metabolic processes such as respiration, biomolecule synthesis, and photosynthesis...
March 1, 2018: Journal of Colloid and Interface Science
J Z Benton, R J Williams, A Patel, K Meichner, J Tarigo, K Nagata, T D Pethel, R M Gogal
Injection Site Sarcomas (ISS) are highly invasive feline malignant tumors that are frequently associated with routine vaccination. Current treatment modalities include chemotherapy, radiation, and radical surgery. ISS have been shown to be one of the most treatment resistant of feline cancers with high rates of recurrence. Previous studies have shown that gold and other high atomic number nanoparticles have the ability to increase the dose of radiation deposited into tissue by generating secondary electrons...
December 2, 2017: Research in Veterinary Science
Jan Krajczewski, Karol Kołątaj, Sylwia Pietrasik, Andrzej Kudelski
One of the tools used for determining the composition of surfaces of various materials is shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS). SHINERS is a modification of "standard" surface-enhanced Raman spectroscopy (SERS), in which, before Raman spectra are recorded, the surfaces analysed are covered with a layer of plasmonic nanoparticles protected by a very thin layer of a transparent dielectric. The plasmonic cores of the core-shell nanoparticles used in SHINERS measurements generate a local enhancement of the electric field of the incident electromagnetic radiation, whereas the transparent coatings prevent the metal cores from coming into direct contact with the material being analysed...
March 15, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Lukas Roloff, Philippe Klemm, Imke Gronwald, Rupert Huber, John M Lupton, Sebastian Bange
Gold nanoparticles emit broad-band upconverted luminescence upon irradiation with pulsed infrared laser radiation. Although the phenomenon is widely observed, considerable disagreement still exists concerning the underlying physics, most notably over the applicability of concepts such as multiphoton absorption, inelastic scattering, and interband vs intraband electronic transitions. Here, we study single particles and small clusters of particles by employing a spectrally resolved power-law analysis of the irradiation-dependent emission as a sensitive probe of these physical models...
December 13, 2017: Nano Letters
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