Au@TiO2 nanocomposites synthesized by X-ray radiolysis as potential radiosensitizers

Higgins, Maria C. Molina; Clifford, Dustin M.; Rojas, Jessika V.

doi:10.1016/j.apsusc.2017.08.094

Cited by 17 publications

(4 citation statements)

References 155 publications

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“…Various supports, such as polymers, oxides, or carbon-based materials, have been used to generate supported metallic nanostructures by ionizing radiation (Figure 7). Common oxides include metallic oxides, such as titanium dioxide (TiO 2 ) [80][81][82], alumina (Al 2 O 3 ) [83,84], silica (SiO 2 ) [85,86], and zinc oxide (ZnO) [87], as well as reduced graphene oxide (rGO) [88][89][90]. Carbon nanotubes also constitute a support of choice [91][92][93].…”

Section: Stabilization Of the Formed Nanostructures And Supported Nan...mentioning

confidence: 99%

Synthesis of Metallic Nanostructures Using Ionizing Radiation and Their Applications

Remita,

Lampre

2024

Materials

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This paper reviews the radiation-induced synthesis of metallic nanostructures and their applications. Radiolysis is a powerful method for synthesizing metallic nanoparticles in solution and heterogeneous media, and it is a clean alternative to other existing physical, chemical, and physicochemical methods. By varying parameters such as the absorbed dose, dose rate, concentrations of metallic precursors, and nature of stabilizing agents, it is possible to control the size, shape, and morphology (alloy, core-shell, etc.) of the nanostructures and, consequently, their properties. Therefore, the as-synthesized nanoparticles have many potential applications in biology, medicine, (photo)catalysis, or energy conversion.

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Section: Stabilization Of the Formed Nanostructures And Supported Nan...mentioning

confidence: 99%

Synthesis of Metallic Nanostructures Using Ionizing Radiation and Their Applications

Remita,

Lampre

2024

Materials

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“…The obtained results evidence the occurrence of sensitization driven by two different mechanisms: in the keV range, the photoelectric effect coupled to the difference in the atomic numbers of the biological tissue and the TiO 2 NPs are responsible of the dose enhancement; when MeV energy is used, the cross section of the photoelectric effect decreases while the active catalytic surfaces of the NPs start to play the major role in the generation of cell killing ROS, leading to the final therapeutic sensitization of RT. The possibility to take advantage of the two mechanisms, i.e., photoelectric and Z-dependent radiosensitization, together with the generation of ROS capable of destroying tumor cells by nanocatalysts, is at the base of the development of novel composite materials, like Au nanoparticles supported on TiO 2 (Au@TiO 2 ), enabling the simultaneous and synergetic establishment of the two processes, which lead to superior performances over the single elements [122].…”

Section: Active Nanoparticles and Catalysts Inducing Ros Generationmentioning

confidence: 99%

Co-Adjuvant Nanoparticles for Radiotherapy Treatments of Oncological Diseases

2021

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Nanomedicine is emerging as promising approach for the implementation of oncological methods. In this review, we describe the most recent methods exploiting heavy nanoparticles and hybrid nanomaterials aiming at improving the traditional X-rays-based treatments. High-Z nanoparticles are proposed as radiosensitizers due to their ability to stop the ionizing radiation and to increase the locally delivered therapeutic dose. Other nanoparticles working as catalysts can generate reactive oxygen species upon X-rays exposure. Thanks to their high toxicity and reactivity, these species promote DNA cancer cells damage and apoptosis. Hybrid nanoparticles, composed by scintillators coupled to organic molecules, are suitable in X-rays activated photodynamic therapy. This work highlights the roles played by the diverse nanoparticles, upon ionizing radiation irradiation, according to their physico-chemical properties, surface functionalization, and targeting strategies. The description of nanoparticle qualities demanded by the oncological nanomedicine is presented in relation to the processes occurring in biological medium when X-ray radiation interacts with heavy nanoparticles, including the scintillation mechanisms, the stopping power amplification, and the disputed modeling of the effective deposit of energy within nanomaterials. The comprehension of these issues in nanomedicine drives the strategies of nanoparticles engineering and paves the way for the development of advanced medical therapies.

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“…However, a higher X-ray flux, especially when focused to a small area of the sample (i.e., high flux density), can lead to undesirable structural and chemical changes that lead to the appearance of intermediates and structures not actually present during catalysis under the same conditions. Such X-ray-induced changes are common and well documented for biological samples and homogeneous catalysts. , For instance, X-rays have been shown to induce the reduction of metal complexes in solution − as well as the nucleation, growth, and agglomeration of nanoparticles. − Similarly, surface-grafted Cu II organometallics on SiO 2 and Al 2 O 3 were easily reduced to Cu I in a high-flux-density X-ray beam, whereas Cu II was stable in a nonfocused beam (low flux density) . However, whereas structural and chemical changes induced by high-energy electron beams are well documented in S/TEM for heterogeneous catalysts, those effects have only recently been shown for XAS .…”

Section: Introductionmentioning

confidence: 99%

Reduction and Agglomeration of Supported Metal Clusters Induced by High-Flux X-ray Absorption Spectroscopy Measurements

et al. 2021

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Supported metal clusters are widely used in catalysis for many important reactions. To understand the catalytic properties, in situ/operando characterization techniques, such as X-ray absorption spectroscopy (XAS), provide essential details of the size, shape, and chemical composition of the cluster and the nature of the active sites. New-generation synchrotrons combined with focusing beamlines provide high-flux-density X-rays for improved detection sensitivity as well as higher time and spatial resolution. Understanding the effects of a high-flux-density X-ray beam on the catalyst during the actual measurement, whether XAS or another synchrotron-based technique, is crucial. This is especially important for in situ and operando studies where both the high flux density and reaction conditions can affect the catalyst structure. In this work, we investigated the effect of the flux density on rhodium clusters supported on Al2O3 at two different beamlines: National Synchrotron Light Source II beamline 08-ID and Stanford Synchrotron Radiation Light Source (SSRL) beamline 4-1. We show that the higher flux density at beamline 08-ID causes the reduction of the highly dispersed RhO x /Al2O3 catalyst, even at room temperature. Additionally, exposure to the higher flux density X-rays at beamline 08-ID during in situ reduction results in significant agglomeration of the Rh clusters. The final size of the Rh nanoparticles reduced at 310 °C is equivalent to that of particles formed after the reduction at 600–650 °C in the absence of the beam. Significant beam-induced reduction and agglomeration is also shown for Ni supported on beta zeolite during in situ reduction at an intermediate-flux-density beamline 9-3 at SSRL, indicating that beam-induced changes in heterogeneous catalysts could be common at intermediate- and high-flux-density beamlines. We provide precautions and recommendations for detecting and minimizing beam damage during in situ/operando XAS measurements.

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Au@TiO2 nanocomposites synthesized by X-ray radiolysis as potential radiosensitizers

Cited by 17 publications

References 155 publications

Synthesis of Metallic Nanostructures Using Ionizing Radiation and Their Applications

Synthesis of Metallic Nanostructures Using Ionizing Radiation and Their Applications

Co-Adjuvant Nanoparticles for Radiotherapy Treatments of Oncological Diseases

Reduction and Agglomeration of Supported Metal Clusters Induced by High-Flux X-ray Absorption Spectroscopy Measurements

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