Nanomaterials

14 pages, 2470 KiB

Open AccessArticle

Electrochemical Synthesis of Mesoporous CoPt Nanowires for Methanol Oxidation

by Albert Serrà, Manuel Montiel, Elvira Gómez and Elisa Vallés^*

Physical Chemistry Department and Institute of Nanoscience and Nanotechnology (IN2UB), University of Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain

Nanomaterials 2014, 4(2), 189-202; https://doi.org/10.3390/nano4020189 - 28 Mar 2014

Cited by 15 | Viewed by 7294

Abstract

A new electrochemical method to synthesize mesoporous nanowires of alloys has been developed. Electrochemical deposition in ionic liquid-in-water (IL/W) microemulsion has been successful to grow mesoporous CoPt nanowires in the interior of polycarbonate membranes. The viscosity of the medium was high, but it [...] Read more.

A new electrochemical method to synthesize mesoporous nanowires of alloys has been developed. Electrochemical deposition in ionic liquid-in-water (IL/W) microemulsion has been successful to grow mesoporous CoPt nanowires in the interior of polycarbonate membranes. The viscosity of the medium was high, but it did not avoid the entrance of the microemulsion in the interior of the membrane’s channels. The structure of the IL/W microemulsions, with droplets of ionic liquid (4 nm average diameter) dispersed in CoPt aqueous solution, defined the structure of the nanowires, with pores of a few nanometers, because CoPt alloy deposited only from the aqueous component of the microemulsion. The electrodeposition in IL/W microemulsion allows obtaining mesoporous structures in which the small pores must correspond to the size of the droplets of the electrolytic aqueous component of the microemulsion. The IL main phase is like a template for the confined electrodeposition. The comparison of the electrocatalytic behaviours towards methanol oxidation of mesoporous and compact CoPt nanowires of the same composition, demonstrated the porosity of the material. For the same material mass, the CoPt mesoporous nanowires present a surface area 16 times greater than compact ones, and comparable to that observed for commercial carbon-supported platinum nanoparticles. Full article

(This article belongs to the Special Issue Ordered Mesoporous Nanomaterials)

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0 pages, 1876 KiB

Open AccessArticle

RETRACTED: Potential Impact of Multi-Walled Carbon Nanotubes Exposure to the Seedling Stage of Selected Plant Species

by Parvin Begum^*, Refi Ikhtiari and Bunshi Fugetsu

Laboratory of Environmental Medical Chemistry, Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810, Japan

Nanomaterials 2014, 4(2), 203-221; https://doi.org/10.3390/nano4020203 - 31 Mar 2014

Cited by 92 | Viewed by 12366 | Retraction

Abstract

Phytotoxicity is a significant consideration in understanding the potential environmental impact of nanoparticles. Abundant experimental data have shown that multi-walled carbon nanotubes (MWNTs) are toxic to plants, but the potential impacts of exposure remain unclear. The objective of the present study was to [...] Read more.

Phytotoxicity is a significant consideration in understanding the potential environmental impact of nanoparticles. Abundant experimental data have shown that multi-walled carbon nanotubes (MWNTs) are toxic to plants, but the potential impacts of exposure remain unclear. The objective of the present study was to evaluate possible phytotoxicity of MWNTs at 0, 20, 200, 1000, and 2000 mg/L with red spinach, lettuce, rice, cucumber, chili, lady’s finger, and soybean, based on root and shoot growth, cell death, and electrolyte leakage at the seedling stage. After 15 days of hydroponic culture, the root and shoot lengths of red spinach, lettuce, and cucumber were significantly reduced following exposure to 1000 mg/L and 2000 mg/L MWNTs. Similar toxic effects occurred regarding cell death and electrolyte leakage. Red spinach and lettuce were most sensitive to MWNTs, followed by rice and cucumber. Very little or no toxic effects were observed for chili, lady’s finger, and soybean. Full article

(This article belongs to the Special Issue Nanotoxicology)

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20 pages, 1022 KiB

Open AccessReview

Recent Advances in the Application of Magnetic Nanoparticles as a Support for Homogeneous Catalysts

by Joseph Govan¹

and Yurii K. Gun'ko^1,2,*

¹ School of Chemistry and CRANN, Trinity College Dublin, Dublin 2, Ireland

² St. Petersburg National Research University of Information Technologies, Mechanics and Optics, St. Petersburg 197101, Russia

Nanomaterials 2014, 4(2), 222-241; https://doi.org/10.3390/nano4020222 - 2 Apr 2014

Cited by 295 | Viewed by 18220

Abstract

Magnetic nanoparticles are a highly valuable substrate for the attachment of homogeneous inorganic and organic containing catalysts. This review deals with the very recent main advances in the development of various nanocatalytic systems by the immobilisation of homogeneous catalysts onto magnetic nanoparticles. We [...] Read more.

Magnetic nanoparticles are a highly valuable substrate for the attachment of homogeneous inorganic and organic containing catalysts. This review deals with the very recent main advances in the development of various nanocatalytic systems by the immobilisation of homogeneous catalysts onto magnetic nanoparticles. We discuss magnetic core shell nanostructures (e.g., silica or polymer coated magnetic nanoparticles) as substrates for catalyst immobilisation. Then we consider magnetic nanoparticles bound to inorganic catalytic mesoporous structures as well as metal organic frameworks. Binding of catalytically active small organic molecules and polymers are also reviewed. After that we briefly deliberate on the binding of enzymes to magnetic nanocomposites and the corresponding enzymatic catalysis. Finally, we draw conclusions and present a future outlook for the further development of new catalytic systems which are immobilised onto magnetic nanoparticles. Full article

(This article belongs to the Special Issue Magnetic Nanomaterials)

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14 pages, 532 KiB

Open AccessArticle

Evaluation of Superparamagnetic Silica Nanoparticles for Extraction of Triazines in Magnetic in-Tube Solid Phase Microextraction Coupled to Capillary Liquid Chromatography

by R. A. González-Fuenzalida¹, Y. Moliner-Martínez¹, Helena Prima-Garcia², Antonio Ribera², P. Campins-Falcó^1,*

and Ramon J. Zaragozá³

¹ Department of Analytical Chemistry. Faculty of Chemistry, University of Valencia, Dr. Moliner 50, Burjassot, Valencia E-46100, Spain

² Instituto de Ciencia Molecular (ICMol), University of Valencia, Catedrático José Beltrán 2, Paterna, Valencia E-46980, Spain

³ Department of Organic Chemistry, Faculty of Chemistry, University of Valencia, Dr. Moliner 50, E-46100 Burjassot, Valencia E-46100, Spain

Nanomaterials 2014, 4(2), 242-255; https://doi.org/10.3390/nano4020242 - 2 Apr 2014

Cited by 28 | Viewed by 7562

Abstract

The use of magnetic nanomaterials for analytical applications has increased in the recent years. In particular, magnetic nanomaterials have shown great potential as adsorbent phase in several extraction procedures due to the significant advantages over the conventional methods. In the present work, the [...] Read more.

The use of magnetic nanomaterials for analytical applications has increased in the recent years. In particular, magnetic nanomaterials have shown great potential as adsorbent phase in several extraction procedures due to the significant advantages over the conventional methods. In the present work, the influence of magnetic forces over the extraction efficiency of triazines using superparamagnetic silica nanoparticles (NPs) in magnetic in tube solid phase microextraction (Magnetic-IT-SPME) coupled to CapLC has been evaluated. Atrazine, terbutylazine and simazine has been selected as target analytes. The superparamagnetic silica nanomaterial (SiO₂-Fe₃O₄) deposited onto the surface of a capillary column gave rise to a magnetic extraction phase for IT-SPME that provided a enhancemment of the extraction efficiency for triazines. This improvement is based on two phenomena, the superparamegnetic behavior of Fe₃O₄ NPs and the diamagnetic repulsions that take place in a microfluidic device such a capillary column. A systematic study of analytes adsorption and desorption was conducted as function of the magnetic field and the relationship with triazines magnetic susceptibility. The positive influence of magnetism on the extraction procedure was demonstrated. The analytical characteristics of the optimized procedure were established and the method was applied to the determination of the target analytes in water samples with satisfactory results. When coupling Magnetic-IT-SPME with CapLC, improved adsorption efficiencies (60%–63%) were achieved compared with conventional adsorption materials (0.8%–3%). Full article

(This article belongs to the Special Issue Magnetic Nanomaterials)

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11 pages, 10924 KiB

Open AccessArticle

NiO Nanofibers as a Candidate for a Nanophotocathode

by Thomas J. Macdonald, Jie Xu, Sait Elmas

, Yatin J. Mange, William M. Skinner, Haolan Xu and Thomas Nann^*

Ian Wark Research Institute, University of South Australia, Mawson Lakes 5095 SA, Australia

Nanomaterials 2014, 4(2), 256-266; https://doi.org/10.3390/nano4020256 - 3 Apr 2014

Cited by 51 | Viewed by 10906

Abstract

p-type NiO nanofibers have been synthesized from a simple electrospinning and sintering procedure. For the first time, p-type nanofibers have been electrospun onto a conductive fluorine doped tin oxide (FTO) surface. The properties of the NiO nanofibers have been directly compared [...] Read more.

p-type NiO nanofibers have been synthesized from a simple electrospinning and sintering procedure. For the first time, p-type nanofibers have been electrospun onto a conductive fluorine doped tin oxide (FTO) surface. The properties of the NiO nanofibers have been directly compared to that of bulk NiO nanopowder. We have observed a p-type photocurrent for a NiO photocathode fabricated on an FTO substrate. Full article

(This article belongs to the Special Issue Nanomaterials in Energy Conversion and Storage)

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34 pages, 2316 KiB

Open AccessReview

Work Function Engineering of Graphene

by Rajni Garg, Naba K. Dutta^* and Namita Roy Choudhury

Ian Wark Research Institute, University of South Australia, Mawson Lakes Campus, 5095 Adelaide, Australia

Nanomaterials 2014, 4(2), 267-300; https://doi.org/10.3390/nano4020267 - 3 Apr 2014

Cited by 274 | Viewed by 45021

Abstract

Graphene is a two dimensional one atom thick allotrope of carbon that displays unusual crystal structure, electronic characteristics, charge transport behavior, optical clarity, physical & mechanical properties, thermal conductivity and much more that is yet to be discovered. Consequently, it has generated unprecedented [...] Read more.

Graphene is a two dimensional one atom thick allotrope of carbon that displays unusual crystal structure, electronic characteristics, charge transport behavior, optical clarity, physical & mechanical properties, thermal conductivity and much more that is yet to be discovered. Consequently, it has generated unprecedented excitement in the scientific community; and is of great interest to wide ranging industries including semiconductor, optoelectronics and printed electronics. Graphene is considered to be a next-generation conducting material with a remarkable band-gap structure, and has the potential to replace traditional electrode materials in optoelectronic devices. It has also been identified as one of the most promising materials for post-silicon electronics. For many such applications, modulation of the electrical and optical properties, together with tuning the band gap and the resulting work function of zero band gap graphene are critical in achieving the desired properties and outcome. In understanding the importance, a number of strategies including various functionalization, doping and hybridization have recently been identified and explored to successfully alter the work function of graphene. In this review we primarily highlight the different ways of surface modification, which have been used to specifically modify the band gap of graphene and its work function. This article focuses on the most recent perspectives, current trends and gives some indication of future challenges and possibilities. Full article

(This article belongs to the Special Issue Nanomaterials in Energy Conversion and Storage)

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18 pages, 1079 KiB

Open AccessArticle

Reproductive Toxicity and Life History Study of Silver Nanoparticle Effect, Uptake and Transport in Arabidopsis thaliana

by Jane Geisler-Lee^1,*, Marjorie Brooks², Jacob R. Gerfen¹, Qiang Wang³, Christin Fotis¹, Anthony Sparer¹, Xingmao Ma³, R. Howard Berg⁴ and Matt Geisler^1,*

¹ Department of Plant Biology, Southern Illinois University Carbondale, Carbondale, IL 62901, USA

² Department of Zoology, Southern Illinois University Carbondale, Carbondale, IL 62901, USA

³ Department of Civil and Environmental Engineering, Southern Illinois University Carbondale, Carbondale, IL 62901, USA

⁴ Integrated Microscopy Facility, The Donald Danforth Plant Science Center, St. Louis, MO 63132, USA

Nanomaterials 2014, 4(2), 301-318; https://doi.org/10.3390/nano4020301 - 22 Apr 2014

Cited by 116 | Viewed by 11934

Abstract

Concerns about nanotechnology have prompted studies on how the release of these engineered nanoparticles impact our environment. Herein, the impact of 20 nm silver nanoparticles (AgNPs) on the life history traits of Arabidopsis thaliana was studied in both above- and below-ground parts, at [...] Read more.

Concerns about nanotechnology have prompted studies on how the release of these engineered nanoparticles impact our environment. Herein, the impact of 20 nm silver nanoparticles (AgNPs) on the life history traits of Arabidopsis thaliana was studied in both above- and below-ground parts, at macroscopic and microscopic scales. Both gross phenotypes (in contrast to microscopic phenotypes) and routes of transport and accumulation were investigated from roots to shoots. Wild type Arabidopsis growing in soil, regularly irrigated with 75 μg/L of AgNPs, did not show any obvious morphological change. However, their vegetative development was prolonged by two to three days and their reproductive growth shortened by three to four days. In addition, the germination rates of offspring decreased drastically over three generations. These findings confirmed that AgNPs induce abiotic stress and cause reproductive toxicity in Arabidopsis. To trace transport of AgNPs, this study also included an Arabidopsis reporter line genetically transformed with a green fluorescent protein and grown in an optical transparent medium with 75 μg/L AgNPs. AgNPs followed three routes: (1) At seven days after planting (DAP) at S1.0 (stages defined by Boyes et al. 2001 [41]), AgNPs attached to the surface of primary roots and then entered their root tips; (2) At 14 DAP at S1.04, as primary roots grew longer, AgNPs gradually moved into roots and entered new lateral root primordia and root hairs; (3) At 17 DAP at S1.06 when the Arabidopsis root system had developed multiple lateral roots, AgNPs were present in vascular tissue and throughout the whole plant from root to shoot. In some cases, if cotyledons of the Arabidopsis seedlings were immersed in melted transparent medium, then AgNPs were taken up by and accumulated in stomatal guard cells. These findings in Arabidopsis are the first to document specific routes and rates of AgNP uptake in vivo and in situ. Full article

(This article belongs to the Special Issue Nanotoxicology)

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12 pages, 1063 KiB

Open AccessArticle

Hyperthermia Using Antibody-Conjugated Magnetic Nanoparticles and Its Enhanced Effect with Cryptotanshinone

by Satoshi Ota¹, Naoya Yamazaki¹, Asahi Tomitaka², Tsutomu Yamada¹ and Yasushi Takemura^1,*

¹ Department of Electrical and Computer Engineering, Yokohama National University, Yokohama 240-8501, Japan

² Department of Materials Science and Engineering, University of Washington, Seattle, WA 98195, USA

Nanomaterials 2014, 4(2), 319-330; https://doi.org/10.3390/nano4020319 - 23 Apr 2014

Cited by 22 | Viewed by 7157

Abstract

Heat dissipation by magnetic nanoparticles (MNPs) under an alternating magnetic field can be used to selectively treat cancer tissues. Antibodies conjugated to MNPs can enhance the therapeutic effects of hyperthermia by altering antibody-antigen interactions. Fe₃O₄ nanoparticles (primary diameter, 20–30 nm) [...] Read more.

Heat dissipation by magnetic nanoparticles (MNPs) under an alternating magnetic field can be used to selectively treat cancer tissues. Antibodies conjugated to MNPs can enhance the therapeutic effects of hyperthermia by altering antibody-antigen interactions. Fe₃O₄ nanoparticles (primary diameter, 20–30 nm) coated with polyethylenimine (PEI) were prepared and conjugated with CH11, an anti-Fas monoclonal antibody. HeLa cell growth was then evaluated as a function of antibody and MNP/antibody complex doses. HeLa cell growth decreased with increased doses of the antibody and complexes. However, MNPs alone did not affect cell growth; thus, only the antibody affected cell growth. In hyperthermia experiments conducted using an alternating magnetic field frequency of 210 kHz, cell viability varied with the intensity of the applied alternating magnetic field, because the temperature increase of the culture medium with added complexes was dependent on magnetic field intensity. The HeLa cell death rate with added complexes was significantly greater as compared with that with MNPs alone. Cryptotanshinone, an anti-apoptotic factor blocker, was also added to cell cultures, which provided an additional anti-cancer cell effect. Thus, an anti-cancer cell effect using a combination of magnetic hyperthermia, an anti-Fas antibody and cryptotanshinone was established. Full article

(This article belongs to the Special Issue Magnetic Nanomaterials)

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13 pages, 2618 KiB

Open AccessArticle

Synthesis Characterization and Photocatalytic Studies of Cobalt Ferrite-Silica-Titania Nanocomposites

by David Greene¹, Raquel Serrano-Garcia¹, Joseph Govan¹

and Yurii K. Gun'ko^1,2,*

¹ School of Chemistry and CRANN, Trinity College Dublin, Dublin 2, Ireland

² St. Petersburg National Research University of Information Technologies, Mechanics and Optics, St. Petersburg 197101, Russia

Nanomaterials 2014, 4(2), 331-343; https://doi.org/10.3390/nano4020331 - 23 Apr 2014

Cited by 59 | Viewed by 12303

Abstract

In this work, CoFe₂O₄@SiO₂@TiO₂ core-shell magnetic nanostructures have been prepared by coating of cobalt ferrite nanoparticles with the double SiO₂/TiO₂ layer using metallorganic precursors. The Transmission Electron Microscopy (TEM), Energy Dispersive X-Ray Analysis [...] Read more.

In this work, CoFe₂O₄@SiO₂@TiO₂ core-shell magnetic nanostructures have been prepared by coating of cobalt ferrite nanoparticles with the double SiO₂/TiO₂ layer using metallorganic precursors. The Transmission Electron Microscopy (TEM), Energy Dispersive X-Ray Analysis (EDX), Vibrational Sample Magnetometer (VSM) measurements and Raman spectroscopy results confirm the presence both of the silica and very thin TiO₂ layers. The core-shell nanoparticles have been sintered at 600 °C and used as a catalyst in photo-oxidation reactions of methylene blue under UV light. Despite the additional non-magnetic coatings result in a lower value of the magnetic moment, the particles can still easily be retrieved from reaction mixtures by magnetic separation. This retention of magnetism was of particular importance allowing magnetic recovery and re-use of the catalyst. Full article

(This article belongs to the Special Issue Magnetic Nanomaterials)

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11 pages, 690 KiB

Open AccessArticle

Directed Kinetic Self-Assembly of Mounds on Patterned GaAs (001): Tunable Arrangement, Pattern Amplification and Self-Limiting Growth

by Chuan-Fu Lin^1,2, Hung-Chih Kan^1,3, Subramaniam Kanakaraju², Christopher Richardson² and Raymond Phaneuf^1,2,*

¹ Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742, USA

² Laboratory for Physical Science, 8050 Greenmead Drive, College Park, MD 20740, USA

³ Department of Physics, National Chung-Cheng University, Chia-Yi 62102, Taiwan

Nanomaterials 2014, 4(2), 344-354; https://doi.org/10.3390/nano4020344 - 12 May 2014

Cited by 2 | Viewed by 6469

Abstract

We present results demonstrating directed self-assembly of nanometer-scale mounds during molecular beam epitaxial growth on patterned GaAs (001) surfaces. The mound arrangement is tunable via the growth temperature, with an inverse spacing or spatial frequency which can exceed that of the features of [...] Read more.

We present results demonstrating directed self-assembly of nanometer-scale mounds during molecular beam epitaxial growth on patterned GaAs (001) surfaces. The mound arrangement is tunable via the growth temperature, with an inverse spacing or spatial frequency which can exceed that of the features of the template. We find that the range of film thickness over which particular mound arrangements persist is finite, due to an evolution of the shape of the mounds which causes their growth to self-limit. A difference in the film thickness at which mounds at different sites self-limit provides a means by which different arrangements can be produced. Full article

(This article belongs to the Special Issue Self-Assembled Nanomaterials)

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17 pages, 1015 KiB

Open AccessArticle

The Impact of Surface Ligands and Synthesis Method on the Toxicity of Glutathione-Coated Gold Nanoparticles

by Bryan Harper¹, Federico Sinche¹, Rosina Ho Wu², Meenambika Gowrishankar², Grant Marquart², Marilyn Mackiewicz² and Stacey L. Harper^1,*

¹ Department of Environmental and Molecular Toxicology, Oregon State University, 1007 ALS Building, Corvallis, OR 97331, USA

² Department of Chemistry, Portland State University, 1719 SW 10th Ave., Portland, OR 97201, USA

Nanomaterials 2014, 4(2), 355-371; https://doi.org/10.3390/nano4020355 - 12 May 2014

Cited by 43 | Viewed by 12963

Abstract

Gold nanoparticles (AuNPs) are increasingly used in biomedical applications, hence understanding the processes that affect their biocompatibility and stability are of significant interest. In this study, we assessed the stability of peptide-capped AuNPs and used the embryonic zebrafish (Danio rerio) as [...] Read more.

Gold nanoparticles (AuNPs) are increasingly used in biomedical applications, hence understanding the processes that affect their biocompatibility and stability are of significant interest. In this study, we assessed the stability of peptide-capped AuNPs and used the embryonic zebrafish (Danio rerio) as a vertebrate system to investigate the impact of synthesis method and purity on their biocompatibility. Using glutathione (GSH) as a stabilizer, Au-GSH nanoparticles with identical core sizes were terminally modified with Tryptophan (Trp), Histidine (His) or Methionine (Met) amino acids and purified by either dialysis or ultracentrifugation. Au-GSH-(Trp)₂ purified by dialysis elicited significant morbidity and mortality at 200 µg/mL, Au-GSH-(His)₂ induced morbidity and mortality after purification by either method at 20 and 200 µg/mL, and Au-GSH-(Met)₂ caused only sublethal responses at 200 µg/mL. Overall, toxicity was significantly reduced and ligand structure was improved by implementing ultracentrifugation purifications at several stages during the multi-step synthesis and surface modification of Au-GSH nanoparticles. When carefully synthesized at high purity, peptide-functionalized AuNPs showed high biocompatibility in biological systems. Full article

(This article belongs to the Special Issue Nanotoxicology)

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36 pages, 1033 KiB

Open AccessReview

Emergent Properties and Toxicological Considerations for Nanohybrid Materials in Aquatic Systems

by Navid B. Saleh¹, A. R. M. Nabiul Afrooz¹, Joseph H. Bisesi,, Jr.², Nirupam Aich¹, Jaime Plazas-Tuttle¹ and Tara Sabo-Attwood^2,*

¹ Department of Civil, Architectural and Environmental Engineering, University of Texas at Austin, Austin, TX 78712, USA

² Department of Environmental and Global Health, Center for Human and Environmental Toxicology, University of Florida, Gainesville, FL 32611, USA

Nanomaterials 2014, 4(2), 372-407; https://doi.org/10.3390/nano4020372 - 3 Jun 2014

Cited by 46 | Viewed by 13487

Abstract

Conjugation of multiple nanomaterials has become the focus of recent materials development. This new material class is commonly known as nanohybrids or “horizon nanomaterials”. Conjugation of metal/metal oxides with carbonaceous nanomaterials and overcoating or doping of one metal with another have been pursued [...] Read more.

Conjugation of multiple nanomaterials has become the focus of recent materials development. This new material class is commonly known as nanohybrids or “horizon nanomaterials”. Conjugation of metal/metal oxides with carbonaceous nanomaterials and overcoating or doping of one metal with another have been pursued to enhance material performance and/or incorporate multifunctionality into nano-enabled devices and processes. Nanohybrids are already at use in commercialized energy, electronics and medical products, which warrant immediate attention for their safety evaluation. These conjugated ensembles likely present a new set of physicochemical properties that are unique to their individual component attributes, hence increasing uncertainty in their risk evaluation. Established toxicological testing strategies and enumerated underlying mechanisms will thus need to be re-evaluated for the assessment of these horizon materials. This review will present a critical discussion on the altered physicochemical properties of nanohybrids and analyze the validity of existing nanotoxicology data against these unique properties. The article will also propose strategies to evaluate the conjugate materials’ safety to help undertake future toxicological research on the nanohybrid material class. Full article

(This article belongs to the Special Issue Nanotoxicology)

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31 pages, 2135 KiB

Open AccessReview

Superparamagnetic Nanoparticles for Atherosclerosis Imaging

by Fernando Herranz^1,2,*, Beatriz Salinas^1,2, Hugo Groult^1,2, Juan Pellico^1,2, Ana V. Lechuga-Vieco^1,2, Riju Bhavesh¹ and J. Ruiz-Cabello^1,2,3

¹ Advanced Imaging Unit, Department of Epidemiology, Atherothrombosis and Imaging, Spanish National Centre for Cardiovascular Research (CNIC), Melchor Fernández Almagro, 3, 28029 Madrid, Spain

² CIBER of Pulmonary Diseases, Biomedical Research Network, Carlos III Health Institute, 28029 Madrid, Spain

³ Department of Physicochemistry II, Faculty of Pharmacy, Complutense University Madrid (UCM), Plaza Ramón y Cajal s/n Ciudad Universitaria, 28040 Madrid, Spain

Nanomaterials 2014, 4(2), 408-438; https://doi.org/10.3390/nano4020408 - 5 Jun 2014

Cited by 27 | Viewed by 15566

Abstract

The production of magnetic nanoparticles of utmost quality for biomedical imaging requires several steps, from the synthesis of highly crystalline magnetic cores to the attachment of the different molecules on the surface. This last step probably plays the key role in the production [...] Read more.

The production of magnetic nanoparticles of utmost quality for biomedical imaging requires several steps, from the synthesis of highly crystalline magnetic cores to the attachment of the different molecules on the surface. This last step probably plays the key role in the production of clinically useful nanomaterials. The attachment of the different biomolecules should be performed in a defined and controlled fashion, avoiding the random adsorption of the components that could lead to undesirable byproducts and ill-characterized surface composition. In this work, we review the process of creating new magnetic nanomaterials for imaging, particularly for the detection of atherosclerotic plaque, in vivo. Our focus will be in the different biofunctionalization techniques that we and several other groups have recently developed. Magnetic nanomaterial functionalization should be performed by chemoselective techniques. This approach will facilitate the application of these nanomaterials in the clinic, not as an exception, but as any other pharmacological compound. Full article

(This article belongs to the Special Issue Magnetic Nanomaterials)

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15 pages, 4197 KiB

Open AccessArticle

Assessment of the Aerosol Generation and Toxicity of Carbon Nanotubes

by Patrick T. O'Shaughnessy^*, Andrea Adamcakova-Dodd, Ralph Altmaier and Peter S. Thorne

The University of Iowa, Department of Occupational and Environmental Health, 100 CPHB S320, Iowa City, IA 52242, USA

Nanomaterials 2014, 4(2), 439-453; https://doi.org/10.3390/nano4020439 - 12 Jun 2014

Cited by 9 | Viewed by 7305

Abstract

Current interest in the pulmonary toxicity of carbon nanotubes (CNTs) has resulted in a need for an aerosol generation system that is capable of consistently producing a CNT aerosol at a desired concentration level. This two-part study was designed to: (1) assess the [...] Read more.

Current interest in the pulmonary toxicity of carbon nanotubes (CNTs) has resulted in a need for an aerosol generation system that is capable of consistently producing a CNT aerosol at a desired concentration level. This two-part study was designed to: (1) assess the properties of a commercially-available aerosol generator when producing an aerosol from a purchased powder supply of double-walled carbon nanotubes (DWCNTs); and (2) assess the pulmonary sub-acute toxicity of DWCNTs in a murine model during a 5-day (4 h/day) whole-body exposure. The aerosol generator, consisting of a novel dustfeed mechanism and venturi ejector was determined to be capable of producing a DWCNT consistently over a 4 h exposure period at an average level of 10.8 mg/m³. The count median diameter was 121 nm with a geometric standard deviation of 2.04. The estimated deposited dose was 32 µg/mouse. The total number of cells in bronchoalveolar lavage (BAL) fluid was significantly (p < 0.01) increased in exposed mice compared to controls. Similarly, macrophages in BAL fluid were significantly elevated in exposed mice, but not neutrophils. All animals exposed to CNT and euthanized immediately after exposure had changes in the lung tissues showing acute inflammation and injury; however these pathological changes resolved two weeks after the exposure. Full article

(This article belongs to the Special Issue Nanotoxicology)

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31 pages, 2369 KiB

Open AccessReview

Mechanisms Underlying Cytotoxicity Induced by Engineered Nanomaterials: A Review of In Vitro Studies

by Daniele R. Nogueira¹, Montserrat Mitjans^2,3

, Clarice M.B. Rolim¹ and M. Pilar Vinardell^2,3,*

¹ Departamento de Farmácia Industrial, Universidade Federal de Santa Maria, Santa Maria, RS, 97105-900, Brazil

² Departament de Fisiologia, Facultat de Farmàcia, Universitat de Barcelona, Barcelona 08028, Spain

³ Unidad Asociada al CSIC, Barcelona 08028, Spain

Nanomaterials 2014, 4(2), 454-484; https://doi.org/10.3390/nano4020454 - 12 Jun 2014

Cited by 50 | Viewed by 10081

Abstract

Engineered nanomaterials are emerging functional materials with technologically interesting properties and a wide range of promising applications, such as drug delivery devices, medical imaging and diagnostics, and various other industrial products. However, concerns have been expressed about the risks of such materials and [...] Read more.

Engineered nanomaterials are emerging functional materials with technologically interesting properties and a wide range of promising applications, such as drug delivery devices, medical imaging and diagnostics, and various other industrial products. However, concerns have been expressed about the risks of such materials and whether they can cause adverse effects. Studies of the potential hazards of nanomaterials have been widely performed using cell models and a range of in vitro approaches. In the present review, we provide a comprehensive and critical literature overview on current in vitro toxicity test methods that have been applied to determine the mechanisms underlying the cytotoxic effects induced by the nanostructures. The small size, surface charge, hydrophobicity and high adsorption capacity of nanomaterial allow for specific interactions within cell membrane and subcellular organelles, which in turn could lead to cytotoxicity through a range of different mechanisms. Finally, aggregating the given information on the relationships of nanomaterial cytotoxic responses with an understanding of its structure and physicochemical properties may promote the design of biologically safe nanostructures. Full article

(This article belongs to the Special Issue Nanotoxicology)

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20 pages, 4191 KiB

Open AccessArticle

Biological Effects of Clinically Relevant CoCr Nanoparticles in the Dura Mater: An Organ Culture Study

by Iraklis Papageorgiou^1,*, Thomas Abberton¹, Martin Fuller¹, Joanne L. Tipper¹, John Fisher² and Eileen Ingham¹

¹ IMBE (Institute of Medical & Biological Engineering), School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK

² IMBE, School of Mechanical Engineering, University of Leeds, Leeds LS2 9JT, UK

Nanomaterials 2014, 4(2), 485-504; https://doi.org/10.3390/nano4020485 - 16 Jun 2014

Cited by 10 | Viewed by 7231

Abstract

Medical interventions for the treatment of spinal disc degeneration include total disc replacement and fusion devices. There are, however, concerns regarding the generation of wear particles by these devices, the majority of which are in the nanometre sized range with the potential to [...] Read more.

Medical interventions for the treatment of spinal disc degeneration include total disc replacement and fusion devices. There are, however, concerns regarding the generation of wear particles by these devices, the majority of which are in the nanometre sized range with the potential to cause adverse biological effects in the surrounding tissues. The aims of this study were to develop an organ culture model of the porcine dura mater and to investigate the biological effects of CoCr nanoparticles in this model. A range of histological techniques were used to analyse the structure of the tissue in the organ culture. The biological effects of the CoCr wear particles and the subsequent structural changes were assessed using tissue viability assays, cytokine assays, histology, immunohistochemistry, and TEM imaging. The physiological structure of the dura mater remained unchanged during the seven days of in vitro culture. There was no significant loss of cell viability. After exposure of the organ culture to CoCr nanoparticles, there was significant loosening of the epithelial layer, as well as the underlying collagen matrix. TEM imaging confirmed these structural alterations. These structural alterations were attributed to the production of MMP-1, -3, -9, -13, and TIMP-1. ELISA analysis revealed that there was significant release of cytokines including IL-8, IL-6, TNF-α, ECP and also the matrix protein, tenascin-C. This study suggested that CoCr nanoparticles did not cause cytotoxicity in the dura mater but they caused significant alterations to its structural integrity that could lead to significant secondary effects due to nanoparticle penetration, such as inflammation to the local neural tissue. Full article

(This article belongs to the Special Issue Nanotoxicology)

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3 pages, 136 KiB

Open AccessEditorial

Magnetic Nanomaterials and Their Applications

by Yurii K. Gun'ko^1,2

¹ School of Chemistry and CRANN, Trinity College Dublin, Dublin 2, Ireland

² St. Petersburg National Research University of Information Technologies, Mechanics and Optics, St. Petersburg 197101, Russia

Nanomaterials 2014, 4(2), 505-507; https://doi.org/10.3390/nano4020505 - 23 Jun 2014

Cited by 3 | Viewed by 6192

Abstract

This Special Issue of Nanomaterials is dedicated to the development of new magnetic nanomaterials and their applications in biomedicine, catalysis, spintronics and other areas. The publications in this Issue demonstrate that the interest in magnetic nanomaterials is continuously growing and their realm is [...] Read more.

This Special Issue of Nanomaterials is dedicated to the development of new magnetic nanomaterials and their applications in biomedicine, catalysis, spintronics and other areas. The publications in this Issue demonstrate that the interest in magnetic nanomaterials is continuously growing and their realm is expanding rapidly. Some highlights of the publications in this issue are discussed below. [...] Full article

(This article belongs to the Special Issue Magnetic Nanomaterials)

14 pages, 206 KiB

Open AccessReview

Carbon Nanotubes and Chronic Granulomatous Disease

by Barbara P. Barna¹, Marc A. Judson² and Mary Jane Thomassen^1,*

¹ Division of Pulmonary, Critical Care and Sleep Medicine, East Carolina University, Brody Medical Sciences Building, 600 Moye Blvd. Rm. 3E-149, Greenville, NC 27834, USA

² Division of Pulmonary and Critical Care Medicine, Albany Medical College, MC-91, 47 New Scotland Avenue, Albany, NY 12208, USA

Nanomaterials 2014, 4(2), 508-521; https://doi.org/10.3390/nano4020508 - 23 Jun 2014

Cited by 19 | Viewed by 6139

Abstract

Use of nanomaterials in manufactured consumer products is a rapidly expanding industry and potential toxicities are just beginning to be explored. Combustion-generated multiwall carbon nanotubes (MWCNT) or nanoparticles are ubiquitous in non-manufacturing environments and detectable in vapors from diesel fuel, methane, propane, and [...] Read more.

Use of nanomaterials in manufactured consumer products is a rapidly expanding industry and potential toxicities are just beginning to be explored. Combustion-generated multiwall carbon nanotubes (MWCNT) or nanoparticles are ubiquitous in non-manufacturing environments and detectable in vapors from diesel fuel, methane, propane, and natural gas. In experimental animal models, carbon nanotubes have been shown to induce granulomas or other inflammatory changes. Evidence suggesting potential involvement of carbon nanomaterials in human granulomatous disease, has been gathered from analyses of dusts generated in the World Trade Center disaster combined with epidemiological data showing a subsequent increase in granulomatous disease of first responders. In this review we will discuss evidence for similarities in the pathophysiology of carbon nanotube-induced pulmonary disease in experimental animals with that of the human granulomatous disease, sarcoidosis. Full article

(This article belongs to the Special Issue Nanotoxicology)

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Nanomaterials, Volume 4, Issue 2 (June 2014) – 19 articles , Pages 189-534

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