Nanomaterials

25 pages, 15384 KiB

Open AccessArticle

Synthesis of the Novel Type of Bimodal Ceramic Nanowires from Polymer and Composite Fibrous Mats

by Tomasz Tański^*

and Wiktor Matysiak^*

Institute of Engineering Materials and Biomaterials, Silesian University of Technology, Konarskiego 18a, 44-100 Gliwice, Poland

Nanomaterials 2018, 8(3), 179; https://doi.org/10.3390/nano8030179 - 20 Mar 2018

Cited by 13 | Viewed by 5004

Abstract

The purpose of this paper was to produce SiO₂ and TiO₂ nanowires via the electrospinning process from a polyvinylpyrrolidone (PVP)/Tetraethyl orthosilicate (TEOS)/Titanium (IV) butoxide (TNBT)/dimethylformamide (DMF) and ethanol (EtOH) solution. The as-obtained nanofibers were calcined at temperatures ranging from 400 °C [...] Read more.

The purpose of this paper was to produce SiO₂ and TiO₂ nanowires via the electrospinning process from a polyvinylpyrrolidone (PVP)/Tetraethyl orthosilicate (TEOS)/Titanium (IV) butoxide (TNBT)/dimethylformamide (DMF) and ethanol (EtOH) solution. The as-obtained nanofibers were calcined at temperatures ranging from 400 °C to 600 °C in order to remove the organic phase. The one-dimensional ceramic nanostructures were studied using a scanning electron microscope (SEM) and a transmission electron microscope (TEM) to analyze the influence of the used temperature on the morphology and structures of the obtained ceramic nanomaterials. In order to examine the chemical structure of the nanowires, energy dispersive spectrometry (EDX) and Fourier-Transform Infrared spectroscopy (FTIR) were used. The optical property analysis was performed on the basis of UV-Vis spectra of absorbance as a function of the wavelength. Using the modified Swanepoel method, which the authors proposed and the recorded absorbance spectra allowed to determine the banded refractive index n, real n′ and imaginary k part of the refractive index as a function of the wavelength, complex dielectric permeability ε, and real and imaginary part ε_r and ε_i of the dielectric permeability as a function of the radiation energy of the produced ceramic nanowires. Full article

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10 pages, 1719 KiB

Open AccessArticle

Transferrin Functionalized Liposomes Loading Dopamine HCl: Development and Permeability Studies across an In Vitro Model of Human Blood–Brain Barrier

by Antonio Lopalco¹, Annalisa Cutrignelli^1,*, Nunzio Denora^1,2, Angela Lopedota¹, Massimo Franco¹ and Valentino Laquintana¹

¹ Department of Pharmacy–Drug Sciences, University of Bari “Aldo Moro”, 4 E. Orabona st, 70125 Bari, Italy

² Institute for Physical and Chemical Processes (IPCF)-CNR, SS Bari, 4 E. Orabona st, 70125 Bari, Italy

Nanomaterials 2018, 8(3), 178; https://doi.org/10.3390/nano8030178 - 20 Mar 2018

Cited by 78 | Viewed by 7172

Abstract

The transport of dopamine across the blood brain barrier represents a challenge for the management of Parkinson’s disease. The employment of central nervous system targeted ligands functionalized nanocarriers could be a valid tactic to overcome this obstacle and avoid undesirable side effects. In [...] Read more.

The transport of dopamine across the blood brain barrier represents a challenge for the management of Parkinson’s disease. The employment of central nervous system targeted ligands functionalized nanocarriers could be a valid tactic to overcome this obstacle and avoid undesirable side effects. In this work, transferrin functionalized dopamine-loaded liposomes were made by a modified dehydration–rehydration technique from hydrogenated soy phosphatidylcoline, cholesterol and 1,2-stearoyl-sn-glycero-3-phosphoethanolamine-N-[carboxy(poly(ethylene glycol)-2000)]. The physical features of the prepared liposomes were established with successive determination of their endothelial permeability across an in vitro model of the blood-brain barrier, constituted by human cerebral microvascular endothelial cells (hCMEC/D3). Functionalized dopamine-loaded liposomes with encapsulation efficiency more than 35% were made with sizes in a range around 180 nm, polydispersity indices of 0.2, and positive zeta potential values (+7.5 mV). Their stability and drug release kinetics were also evaluated. The apparent permeability (P_e) values of encapsulated dopamine in functionalized and unfunctionalized liposomes showed that transferrin functionalized nanocarriers could represent appealing non-toxic candidates for brain delivery, thus improving benefits and decreasing complications to patients subjected to L-dopa chronical treatment. Full article

(This article belongs to the Special Issue Nanocolloids for Nanomedicine and Drug Delivery)

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26 pages, 6387 KiB

Open AccessFeature PaperArticle

TiO₂-SiO₂ Coatings with a Low Content of AuNPs for Producing Self-Cleaning Building Materials

by Manuel Luna¹

, Juan J. Delgado²

, M. L. Almoraima Gil¹ and María J. Mosquera^1,*

¹ TEP-243 Nanomaterials Group, Department of Physical-Chemistry, Faculty of Sciences, University of Cadiz, 11510 Puerto Real, Spain

² Department of Inorganic Chemistry, CASEM, University of Cadiz, 11510 Puerto Real, Spain

Nanomaterials 2018, 8(3), 177; https://doi.org/10.3390/nano8030177 - 20 Mar 2018

Cited by 37 | Viewed by 6540

Abstract

The high pollution levels in our cities are producing a significant increase of dust on buildings. An application of photoactive coatings on building materials can produce buildings with self-cleaning surfaces. In this study, we have developed a simple sol-gel route for producing Au-TiO [...] Read more.

The high pollution levels in our cities are producing a significant increase of dust on buildings. An application of photoactive coatings on building materials can produce buildings with self-cleaning surfaces. In this study, we have developed a simple sol-gel route for producing Au-TiO₂/SiO₂ photocatalysts with application on buildings. The gold nanoparticles (AuNPs) improved the TiO₂ photoactivity under solar radiation because they promoted absorption in the visible range. We varied the content of AuNPs in the sols under study, in order to investigate their effect on self-cleaning properties. The sols obtained were sprayed on a common building stone, producing coatings which adhere firmly to the stone and preserve their aesthetic qualities. We studied the decolourization efficiency of the photocatalysts under study against methylene blue and against soot (a real staining agent for buildings). Finally, we established that the coating with an intermediate Au content presented the best self-cleaning performance, due to the role played by its structure and texture on its photoactivity. Full article

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14 pages, 7522 KiB

Open AccessFeature PaperArticle

Comparison of Branched and Linear Perfluoropolyether Chains Functionalization on Hydrophobic, Morphological and Conductive Properties of Multi-Walled Carbon Nanotubes

by Maurizio Sansotera^1,2,*, Sadaf Talaeemashhadi¹, Cristian Gambarotti^1,2, Carlo Pirola^3,4

, Mariangela Longhi³

, Marco A. Ortenzi³

, Walter Navarrini^1,2 and Claudia L. Bianchi^3,4,*

¹ Dipartimento di Chimica, Materiali e Ingegneria Chimica, Politecnico di Milano, via Mancinelli 7, I-20131 Milano, Italy

² Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali (UdR-PoliMi), via G. Giusti, 9, 50121 Firenze, Italy

³ Dipartimento di Chimica, Università degli Studi di Milano, via Golgi 19, I-20133 Milano, Italy

⁴ Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali (UdR-UniMi), via G. Giusti, 9, 50121 Firenze, Italy

Nanomaterials 2018, 8(3), 176; https://doi.org/10.3390/nano8030176 - 19 Mar 2018

Cited by 5 | Viewed by 5276

Abstract

The functionalization of multi-walled carbon nanotubes (MW-CNTs) was obtained by generating reactive perfluoropolyether (PFPE) radicals that can covalently bond to MW-CNTs’ surface. Branched and linear PFPE peroxides with equivalent molecular weights of 1275 and 1200 amu, respectively, have been thermally decomposed for the [...] Read more.

The functionalization of multi-walled carbon nanotubes (MW-CNTs) was obtained by generating reactive perfluoropolyether (PFPE) radicals that can covalently bond to MW-CNTs’ surface. Branched and linear PFPE peroxides with equivalent molecular weights of 1275 and 1200 amu, respectively, have been thermally decomposed for the production of PFPE radicals. The functionalization with PFPE chains has changed the wettability of MW-CNTs, which switched their behavior from hydrophilic to super-hydrophobic. The low surface energy properties of PFPEs have been transferred to MW-CNTs surface and branched units with trifluoromethyl groups, CF₃, have conferred higher hydrophobicity than linear units. Porosimetry discriminated the effects of PFPE functionalization on meso-porosity and macro-porosity. It has been observed that reactive sites located in MW-CNTs mesopores have been intensively functionalized by branched PFPE peroxide due to its low average molecular weight. Conductivity measurements at different applied pressures have showed that the covalent linkage of PFPE chains, branched as well as linear, weakly modified the electrical conductivity of MW-CNTs. The decomposed portions of PFPE residues, the PFPE chains bonded on carbon nanotubes, and the PFPE fluids obtained by homo-coupling side-reactions were evaluated by mass balances. PFPE-modified MW-CNTs have been characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), static contact angle (SCA), surface area, and porosity measurements. Full article

(This article belongs to the Special Issue Preparation and Application of Hybrid Nanomaterials)

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8 pages, 2551 KiB

Open AccessArticle

Plasmonic Absorption Enhancement in Elliptical Graphene Arrays

by Jiajia Chen^1,2, Yu Zeng^1,2, Xibin Xu³, Xifang Chen^1,2, Zigang Zhou^1,2, Pengcheng Shi^1,2, Zao Yi^1,2,*

, Xin Ye^3,*, Shuyuan Xiao^4,*

and Yougen Yi⁵

¹ School of Science, Southwest University of Science and Technology, Mianyang 621010, China

² Joint Laboratory for Extreme Conditions Matter Properties, Southwest University of Science and Technology, Mianyang 621010, China

³ Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China

⁴ Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China

⁵ College of Physics and Electronics, Central South University, Changsha 410083, China

Nanomaterials 2018, 8(3), 175; https://doi.org/10.3390/nano8030175 - 19 Mar 2018

Cited by 49 | Viewed by 5828

Abstract

In this paper, we come up with a wavelength tunable absorber which is made up of periodically elliptical graphene arrays in the far-infrared and terahertz regions. Through simulation, we find that we can increase the length of long axis of the ellipse, raise [...] Read more.

In this paper, we come up with a wavelength tunable absorber which is made up of periodically elliptical graphene arrays in the far-infrared and terahertz regions. Through simulation, we find that we can increase the length of long axis of the ellipse, raise the incidence angles of TM- and TE-polarization (TM- and TE-polarization indicate the direction of the incident electric field along the direction of the x and the y axis, respectively.) within certain limits, and increase the chemical potential of graphene, so as to enhance the absorption of light in the elliptical graphene arrays. We also compare the absorption spectra of the original structure and the complementary structure, and find that the absorption of the original structure is higher than that of the complementary structure. In the end, we study the changes in the absorption rate of the double layer structure of the elliptical array with the increase in the thickness of SiO₂. The elliptical array structure can be applied to tunable spectral detectors, filters and sensors at far-infrared and terahertz wavelengths. Full article

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15 pages, 4653 KiB

Open AccessArticle

Synthesis of Gold Nanoparticles Using Leaf Extract of Ziziphus zizyphus and their Antimicrobial Activity

by Alaa A. A. Aljabali^1,*

, Yazan Akkam¹, Mazhar Salim Al Zoubi²

, Khalid M. Al-Batayneh³

, Bahaa Al-Trad³

, Osama Abo Alrob¹, Alaaldin M. Alkilany⁴, Mourad Benamara⁵ and David J. Evans⁶

¹ Faculty of Pharmacy, Yarmouk University, P.O.BOX 566, Irbid 21163, Jordan

² Department of Basic Medical Sciences, Faculty of Medicine, Yarmouk University, Irbid 21163, Jordan

³ Department of Biological Science, Yarmouk University, P.O.BOX 566, Irbid 21163, Jordan

⁴ School of Pharmacy, University of Jordan, Aljubeiha, Amman, Jordan 11942, Jordan

⁵ Institute for Nanoscience, University of Arkansas, Fayetteville, AR 72701, USA

⁶ John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK

Nanomaterials 2018, 8(3), 174; https://doi.org/10.3390/nano8030174 - 19 Mar 2018

Cited by 295 | Viewed by 14467

Abstract

(1) Background: There is a growing need for the development of new methods for the synthesis of nanoparticles. The interest in such particles has raised concerns about the environmental safety of their production methods; (2) Objectives: The current methods of nanoparticle production are [...] Read more.

(1) Background: There is a growing need for the development of new methods for the synthesis of nanoparticles. The interest in such particles has raised concerns about the environmental safety of their production methods; (2) Objectives: The current methods of nanoparticle production are often expensive and employ chemicals that are potentially harmful to the environment, which calls for the development of “greener” protocols. Herein we describe the synthesis of gold nanoparticles (AuNPs) using plant extracts, which offers an alternative, efficient, inexpensive, and environmentally friendly method to produce well-defined geometries of nanoparticles; (3) Methods: The phytochemicals present in the aqueous leaf extract acted as an effective reducing agent. The generated AuNPs were characterized by Transmission electron microscopy (TEM), Scanning electron microscope (SEM), and Atomic Force microscopy (AFM), X-ray diffraction (XRD), UV-visible spectroscopy, energy dispersive X-ray (EDX), and thermogravimetric analyses (TGA); (4) Results and Conclusions: The prepared nanoparticles were found to be biocompatible and exhibited no antimicrobial or antifungal effect, deeming the particles safe for various applications in nanomedicine. TGA analysis revealed that biomolecules, which were present in the plant extract, capped the nanoparticles and acted as stabilizing agents. Full article

(This article belongs to the Special Issue Antibacterial Activity of Nanomaterials)

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13 pages, 3214 KiB

Open AccessArticle

The Adsorption of Dextranase onto Mg/Fe-Layered Double Hydroxide: Insight into the Immobilization

by Yi Ding^1,2,3, Le Liu^1,2,3, Yaowei Fang^1,2,3, Xu Zhang⁴, Mingsheng Lyu^1,2,3,* and Shujun Wang^1,2,3,*

¹ College of Marine Life and Fisheries, Huaihai Institute of Technology, Lianyungang 222005, China

² Jiangsu Institute of Marine Resources Development, Huaihai Institute of Technology, Lianyungang 222005, China

³ Co-Innovation Center of Jiangsu Marine Bio-industry Technology, Huaihai Institute of Technology, Lianyungang 222005, China

⁴ Verschuren Centre for Sustainability in Energy & the Environment, Cape Breton University, Sydney, NS B1P 6L2, Canada

Nanomaterials 2018, 8(3), 173; https://doi.org/10.3390/nano8030173 - 19 Mar 2018

Cited by 19 | Viewed by 5319

Abstract

We report the adsorption of dextranase on a Mg/Fe-layered double hydroxide (Mg/Fe-LDH). We focused the effects of different buffers, pH, and amino acids. The Mg/Fe-LDH was synthesized, and adsorption experiments were performed to investigate the effects. The maximum adsorption occurred in pH 7.0 [...] Read more.

We report the adsorption of dextranase on a Mg/Fe-layered double hydroxide (Mg/Fe-LDH). We focused the effects of different buffers, pH, and amino acids. The Mg/Fe-LDH was synthesized, and adsorption experiments were performed to investigate the effects. The maximum adsorption occurred in pH 7.0 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer, and the maximum dextranase adsorption uptake was 1.38 mg/g (416.67 U/mg); histidine and phenylalanine could affect the adsorption. A histidine tag could be added to the protein to increase the adsorption significantly. The performance features and mechanism were investigated with X-ray diffraction patterns (XRD) and Fourier transform infrared spectra (FTIR). The protein could affect the crystal structure of LDH, and the enzyme was adsorbed on the LDH surface. The main interactions between the protein and LDH were electrostatic and hydrophobic. Histidine and phenylalanine could significantly affect the adsorption. The hexagonal morphology of LDH was not affected after adsorption. Full article

(This article belongs to the Special Issue Layered Double Hydroxide-Based Nanomaterials – From Fundamentals to Applications)

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8 pages, 1386 KiB

Open AccessArticle

Investigation on the Stability of Derivative Melam from Melamine Pyrolysis under High Pressure

by Xiaohong Yuan¹, Kun Luo^1,2

, Yingju Wu¹, Julong He¹, Zhisheng Zhao^1,*

and Dongli Yu^1,*

¹ State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China

² Hebei Key Laboratory of Microstructural Material Physics, School of Science, Yanshan University, Qinhuangdao 066004, China

Nanomaterials 2018, 8(3), 172; https://doi.org/10.3390/nano8030172 - 18 Mar 2018

Cited by 26 | Viewed by 6791

Abstract

Although various kinds of carbon nitride precursors have been proposed, s-triazine-based structures are hardly reported because of their unfavorable energy, higher than that of heptazine-based ones. In this study, we investigate the thermal stability of s-triazine-based melam processed at a high pressure of [...] Read more.

Although various kinds of carbon nitride precursors have been proposed, s-triazine-based structures are hardly reported because of their unfavorable energy, higher than that of heptazine-based ones. In this study, we investigate the thermal stability of s-triazine-based melam processed at a high pressure of 5 GPa and a temperature of 400–700 °C and complete the analyses of the composition and structure of the treated samples through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and elemental analyses (EA). Results show that melam can stably exist up to 600 °C at 5 GPa. XRD and FTIR analyses reveal that residual melamine can be pyrolyzed into melam as temperature increases from 400 °C to 600 °C at a high pressure, suggesting that melam may be purified through high-pressure pyrolysis. Further melam polymerization at a higher pressure is a promising strategy for the preparation of s-triazine-based carbon nitride precursors used for bulk carbon nitride synthesis. Full article

(This article belongs to the Special Issue Graphitic Carbon Nitride Nanostructures: Catalysis and Beyond)

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29 pages, 4734 KiB

Open AccessFeature PaperReview

Preparation, Modification, Characterization, and Biosensing Application of Nanoporous Gold Using Electrochemical Techniques

by Jay K. Bhattarai

, Dharmendra Neupane, Bishal Nepal, Vasilii Mikhaylov, Alexei V. Demchenko

and Keith J. Stine^*

Department of Chemistry and Biochemistry, University of Missouri, St. Louis, Saint Louis, MO 63121, USA

Nanomaterials 2018, 8(3), 171; https://doi.org/10.3390/nano8030171 - 16 Mar 2018

Cited by 72 | Viewed by 9401

Abstract

Nanoporous gold (np-Au), because of its high surface area-to-volume ratio, excellent conductivity, chemical inertness, physical stability, biocompatibility, easily tunable pores, and plasmonic properties, has attracted much interested in the field of nanotechnology. It has promising applications in the fields of catalysis, bio/chemical sensing, [...] Read more.

Nanoporous gold (np-Au), because of its high surface area-to-volume ratio, excellent conductivity, chemical inertness, physical stability, biocompatibility, easily tunable pores, and plasmonic properties, has attracted much interested in the field of nanotechnology. It has promising applications in the fields of catalysis, bio/chemical sensing, drug delivery, biomolecules separation and purification, fuel cell development, surface-chemistry-driven actuation, and supercapacitor design. Many chemical and electrochemical procedures are known for the preparation of np-Au. Recently, researchers are focusing on easier and controlled ways to tune the pores and ligaments size of np-Au for its use in different applications. Electrochemical methods have good control over fine-tuning pore and ligament sizes. The np-Au electrodes that are prepared using electrochemical techniques are robust and are easier to handle for their use in electrochemical biosensing. Here, we review different electrochemical strategies for the preparation, post-modification, and characterization of np-Au along with the synergistic use of both electrochemistry and np-Au for applications in biosensing. Full article

(This article belongs to the Special Issue Nanoporous Gold and Other Related Materials)

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17 pages, 10059 KiB

Open AccessArticle

Cyclodextrin-Based Magnetic Nanoparticles for Cancer Therapy

by Radosław Mrówczyński^1,*

, Artur Jędrzak^1,2, Kosma Szutkowski^1,*

, Bartosz F. Grześkowiak¹, Emerson Coy¹

, Roksana Markiewicz¹

, Teofil Jesionowski²

and Stefan Jurga¹

¹ NanoBioMedical Centre, Adam Mickiewicz University in Poznan, Umultowska 85, PL-61614 Poznan, Poland

² Faculty of Chemical Technology, Institute of Chemical Technology and Engineering, Poznan University of Technology, Berdychowo 4, PL-60965 Poznan, Poland

Nanomaterials 2018, 8(3), 170; https://doi.org/10.3390/nano8030170 - 16 Mar 2018

Cited by 70 | Viewed by 7924

Abstract

Polydopamine (PDA)-coated magnetic nanoparticles functionalized with mono-6-thio-β-cyclodextrin (SH-βCD) were obtained and characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Nuclear and Magnetic Resonance Imaging (NMR and MRI), and doxorubicin (DOXO)-loading experiments. The liver cancer cellular internalization [...] Read more.

Polydopamine (PDA)-coated magnetic nanoparticles functionalized with mono-6-thio-β-cyclodextrin (SH-βCD) were obtained and characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Nuclear and Magnetic Resonance Imaging (NMR and MRI), and doxorubicin (DOXO)-loading experiments. The liver cancer cellular internalization of DOXO-loaded nanoparticles was investigated by confocal imaging microscopy. Synthesized nanomaterials bearing a chemotherapeutic drug and a layer of polydopamine capable of absorbing near-infrared light show high performance in the combined chemo- and photothermal therapy (CT-PTT) of liver cancer due to the synergistic effect of both modalities as demonstrated in vitro. Moreover, our material exhibits improved T₂ contrast properties, which have been verified using Carr-Purcell-Meiboom-Gill pulse sequence and MRI Spin-Echo imaging of the nanoparticles dispersed in the agarose gel phantoms. Therefore, the presented results cast new light on the preparation of polydopamine-based magnetic theranostic nanomaterials, as well as on the proper methodology for investigation of magnetic nanoparticles in high field MRI experiments. The prepared material is a robust theranostic nanoasystem with great potential in nanomedicine. Full article

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10 pages, 1580 KiB

Open AccessArticle

Strongly Iridescent Hybrid Photonic Sensors Based on Self-Assembled Nanoparticles for Hazardous Solvent Detection

by Ayaka Sato, Yuya Ikeda, Koichi Yamaguchi and Varun Vohra^*

Department of Engineering Science, the University of Electro-communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan

Nanomaterials 2018, 8(3), 169; https://doi.org/10.3390/nano8030169 - 16 Mar 2018

Cited by 10 | Viewed by 5274

Abstract

Facile detection and the identification of hazardous organic solvents are essential for ensuring global safety and avoiding harm to the environment caused by industrial wastes. Here, we present a simple method for the fabrication of silver-coated monodisperse polystyrene nanoparticle photonic structures that are [...] Read more.

Facile detection and the identification of hazardous organic solvents are essential for ensuring global safety and avoiding harm to the environment caused by industrial wastes. Here, we present a simple method for the fabrication of silver-coated monodisperse polystyrene nanoparticle photonic structures that are embedded into a polydimethylsiloxane (PDMS) matrix. These hybrid materials exhibit a strong green iridescence with a reflectance peak at 550 nm that originates from the close-packed arrangement of the nanoparticles. This reflectance peak measured under Wulff-Bragg conditions displays a 20 to 50 nm red shift when the photonic sensors are exposed to five commonly employed and highly hazardous organic solvents. These red-shifts correlate well with PDMS swelling ratios using the various solvents, which suggests that the observable color variations result from an increase in the photonic crystal lattice parameter with a similar mechanism to the color modulation of the chameleon skin. Dynamic reflectance measurements enable the possibility of clearly identifying each of the tested solvents. Furthermore, as small amounts of hazardous solvents such as tetrahydrofuran can be detected even when mixed with water, the nanostructured solvent sensors we introduce here could have a major impact on global safety measures as innovative photonic technology for easily visualizing and identifying the presence of contaminants in water. Full article

(This article belongs to the Special Issue Design and Development of Nanostructured Thin Films)

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19 pages, 7291 KiB

Open AccessArticle

Supramolecular Control over the Interparticle Distance in Gold Nanoparticle Arrays by Cyclodextrin Polyrotaxanes

by Joao Paulo Coelho¹, José Osío Barcina², Elena Junquera¹

, Emilio Aicart¹, Gloria Tardajos¹, Sergio Gómez-Graña³

, Pablo Cruz-Gil², Cástor Salgado², Pablo Díaz-Núñez⁴, Ovidio Peña-Rodríguez⁴

and Andrés Guerrero-Martínez^1,*

¹ Departamento de Química Física, Universidad Complutense de Madrid, Avenida Complutense s/n, 28040 Madrid, Spain

² Departamento de Química Orgánica, Universidad Complutense de Madrid, Avenida Complutense s/n, 28040 Madrid, Spain

³ Departamento de Química en Ciencias Farmacéuticas, Universidad Complutense de Madrid, Plaza Ramón y Cajal s/n, 28040 Madrid, Spain

⁴ Instituto de Fusión Nuclear, Universidad Politécnica de Madrid, José Gutiérrez Abascal 2, 28006 Madrid, Spain

Nanomaterials 2018, 8(3), 168; https://doi.org/10.3390/nano8030168 - 16 Mar 2018

Cited by 9 | Viewed by 6631

Abstract

Amphiphilic nonionic ligands, synthesized with a fixed hydrophobic moiety formed by a thiolated alkyl chain and an aromatic ring, and with a hydrophilic tail composed of a variable number of oxyethylene units, were used to functionalize spherical gold nanoparticles (AuNPs) in water. Steady-state [...] Read more.

Amphiphilic nonionic ligands, synthesized with a fixed hydrophobic moiety formed by a thiolated alkyl chain and an aromatic ring, and with a hydrophilic tail composed of a variable number of oxyethylene units, were used to functionalize spherical gold nanoparticles (AuNPs) in water. Steady-state and time-resolved fluorescence measurements of the AuNPs in the presence of α-cyclodextrin (α-CD) revealed the formation of supramolecular complexes between the ligand and macrocycle at the surface of the nanocrystals. The addition of α-CD induced the formation of inclusion complexes with a high apparent binding constant that decreased with the increasing oxyethylene chain length. The formation of polyrotaxanes at the surface of AuNPs, in which many α-CDs are trapped as hosts on the long and linear ligands, was demonstrated by the formation of large and homogeneous arrays of self-assembled AuNPs with hexagonal close packing, where the interparticle distance increased with the length of the oxyethylene chain. The estimated number of α-CDs per polyrotaxane suggests a high rigidization of the ligand upon complexation, allowing for nearly perfect control of the interparticle distance in the arrays. This degree of supramolecular control was extended to arrays formed by AuNPs stabilized with polyethylene glycol and even to binary arrays. Electromagnetic simulations showed that the enhancement and distribution of the electric field can be finely controlled in these plasmonic arrays. Full article

(This article belongs to the Special Issue Supramolecular Nano-architectures)

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18 pages, 19004 KiB

Open AccessArticle

A Modular Coassembly Approach to All-In-One Multifunctional Nanoplatform for Synergistic Codelivery of Doxorubicin and Curcumin

by Muyang Yang^1,2,3, Lixia Yu^1,2, Ruiwei Guo^1,2, Anjie Dong^1,2, Cunguo Lin³ and Jianhua Zhang^1,4,*

¹ Department of Polymer Science and Technology, Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China

² Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China

³ State Key Laboratory for Marine Corrosion and Protection, Luoyang Ship Material Research Institute (LSMRI), Qingdao 266101, China

⁴ Tianjin Key Laboratory of Membrane Science and Desalination Technology, Tianjin University, Tianjin 300072, China

Nanomaterials 2018, 8(3), 167; https://doi.org/10.3390/nano8030167 - 15 Mar 2018

Cited by 30 | Viewed by 5999

Abstract

Synergistic combination therapy by integrating chemotherapeutics and chemosensitizers into nanoparticles has demonstrated great potential to reduce side effects, overcome multidrug resistance (MDR), and thus improve therapeutic efficacy. However, with regard to the nanocarriers for multidrug codelivery, it remains a strong challenge to maintain [...] Read more.

Synergistic combination therapy by integrating chemotherapeutics and chemosensitizers into nanoparticles has demonstrated great potential to reduce side effects, overcome multidrug resistance (MDR), and thus improve therapeutic efficacy. However, with regard to the nanocarriers for multidrug codelivery, it remains a strong challenge to maintain design simplicity, while incorporating the desirable multifunctionalities, such as coloaded high payloads, targeted delivery, hemodynamic stability, and also to ensure low drug leakage before reaching the tumor site, but simultaneously the corelease of drugs in the same cancer cell. Herein, we developed a facile modular coassembly approach to construct an all-in-one multifunctional multidrug delivery system for the synergistic codelivery of doxorubicin (DOX, chemotherapeutic agent) and curcumin (CUR, MDR modulator). The acid-cleavable PEGylated polymeric prodrug (DOX-h-PCEC), tumor cell-specific targeting peptide (CRGDK-PEG-PCL), and natural chemosensitizer (CUR) were ratiometrically assembled into in one single nanocarrier (CUR/DOX-h-PCEC@CRGDK NPs). The resulting CUR/DOX-h-PCEC@CRGDK NPs exhibited several desirable characteristics, such as efficient and ratiometric drug loading, high hemodynamic stability and low drug leakage, tumor intracellular acid-triggered cleavage, and subsequent intracellular simultaneous drug corelease, which are expected to maximize a synergistic effect of chemotherapy and chemosensitization. Collectively, the multifunctional nanocarrier is feasible for the creation of a robust nanoplatform for targeted multidrug codelivery and efficient MDR modulation. Full article

(This article belongs to the Special Issue Self-Assembled Bio-Nanomaterials: Synthesis, Characterization, and Applications)

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16 pages, 9528 KiB

Open AccessArticle

The Hydrolytic Stability and Degradation Mechanism of a Hierarchically Porous Metal Alkylphosphonate Framework

by Kai Lv^*, Chu-Ting Yang, Yi Liu, Sheng Hu and Xiao-Lin Wang

Radiochemistry Lab, Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, P.O. Box 919, Mianyang 621900, Sichuan, China

Nanomaterials 2018, 8(3), 166; https://doi.org/10.3390/nano8030166 - 14 Mar 2018

Cited by 8 | Viewed by 4624

Abstract

To aid the design of a hierarchically porous unconventional metal-phosphonate framework (HP-UMPF) for practical radioanalytical separation, a systematic investigation of the hydrolytic stability of bulk phase against acidic corrosion has been carried out for an archetypical HP-UMPF. Bulk dissolution results suggest that aqueous [...] Read more.

To aid the design of a hierarchically porous unconventional metal-phosphonate framework (HP-UMPF) for practical radioanalytical separation, a systematic investigation of the hydrolytic stability of bulk phase against acidic corrosion has been carried out for an archetypical HP-UMPF. Bulk dissolution results suggest that aqueous acidity has a more paramount effect on incongruent leaching than the temperature, and the kinetic stability reaches equilibrium by way of an accumulation of a partial leached species on the corrosion conduits. A variation of particle morphology, hierarchical porosity and backbone composition upon corrosion reveals that they are hydrolytically resilient without suffering any great degradation of porous texture, although large aggregates crack into sporadic fractures while the nucleophilic attack of inorganic layers cause the leaching of tin and phosphorus. The remaining selectivity of these HP-UMPFs is dictated by a balance between the elimination of free phosphonate and the exposure of confined phosphonates, thus allowing a real-time tailor of radionuclide sequestration. Moreover, a plausible degradation mechanism has been proposed for the triple progressive dissolution of three-level hierarchical porous structures to elucidate resultant reactivity. These HP-UMPFs are compared with benchmark metal-organic frameworks (MOFs) to obtain a rough grading of hydrolytic stability and two feasible approaches are suggested for enhancing their hydrolytic stability that are intended for real-life separation protocols. Full article

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17 pages, 6612 KiB

Open AccessArticle

The Effect of Laminin Surface Modification of Electrospun Silica Nanofiber Substrate on Neuronal Tissue Engineering

by Wen Shuo Chen¹, Ling Yu Guo¹, Chia Chun Tang¹, Cheng Kang Tsai¹, Hui Hua Huang¹, Ting Yu Chin², Mong-Lin Yang^3,*

and Yui Whei Chen-Yang^1,*

¹ Center for Nanotechnology, Center for Biomedical Technology, Department of Chemistry, Chung Yuan Christian University, Taoyuan 32023, Taiwan

² Department of Bioscience Technology, Chung Yuan Christian University, Taoyuan 32023, Taiwan

³ Department of Science, Concordia University Saint Paul, Saint Paul, MN 55104, USA

Nanomaterials 2018, 8(3), 165; https://doi.org/10.3390/nano8030165 - 14 Mar 2018

Cited by 31 | Viewed by 7069

Abstract

In this study, we first synthesized a slow-degrading silica nanofiber (SNF2) through an electrospun solution with an optimized tetraethyl orthosilicate (TEOS) to polyvinyl pyrrolidone (PVP) ratio. Then, laminin-modified SNF2, namely SNF2-AP-S-L, was obtained through a series of chemical reactions to attach the extracellular [...] Read more.

In this study, we first synthesized a slow-degrading silica nanofiber (SNF2) through an electrospun solution with an optimized tetraethyl orthosilicate (TEOS) to polyvinyl pyrrolidone (PVP) ratio. Then, laminin-modified SNF2, namely SNF2-AP-S-L, was obtained through a series of chemical reactions to attach the extracellular matrix protein, laminin, to its surface. The SNF2-AP-S-L substrate was characterized by a combination of scanning electron microscopy (SEM), Fourier transform–infrared (FTIR) spectroscopy, nitrogen adsorption/desorption isotherms, and contact angle measurements. The results of further functional assays show that this substrate is a biocompatible, bioactive and biodegradable scaffold with good structural integrity that persisted beyond 18 days. Moreover, a synergistic effect of sustained structure support and prolonged biochemical stimulation for cell differentiation on SNF2-AP-S-L was found when neuron-like PC12 cells were seeded onto its surface. Specifically, neurite extensions on the covalently modified SNF2-AP-S-L were significantly longer than those observed on unmodified SNF and SNF subjected to physical adsorption of laminin. Together, these results indicate that the SNF2-AP-S-L substrate prepared in this study is a promising 3D biocompatible substrate capable of sustaining longer neuronal growth for tissue-engineering applications. Full article

(This article belongs to the Special Issue Functional Nanomaterials by Electrospinning)

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11 pages, 3025 KiB

Open AccessArticle

Enhancing the Microparticle Deposition Stability and Homogeneity on Planer for Synthesis of Self-Assembly Monolayer

by An-Ci Shih, Chi-Jui Han, Tsung-Cheng Kuo and Yun-Chien Cheng^*

Department of Mechanical Engineering, National Chiao Tung University, Hsinchu 300, Taiwan

Nanomaterials 2018, 8(3), 164; https://doi.org/10.3390/nano8030164 - 14 Mar 2018

Cited by 3 | Viewed by 4034

Abstract

The deposition stability and homogeneity of microparticles improved with mask, lengthened nozzle and flow rate adjustment. The microparticles can be used to encapsulate monomers, before the monomers in the microparticles can be deposited onto a substrate for nanoscale self-assembly. For the uniformity of [...] Read more.

The deposition stability and homogeneity of microparticles improved with mask, lengthened nozzle and flow rate adjustment. The microparticles can be used to encapsulate monomers, before the monomers in the microparticles can be deposited onto a substrate for nanoscale self-assembly. For the uniformity of the synthesized nanofilm, the homogeneity of the deposited microparticles becomes an important issue. Based on the ANSYS simulation results, the effects of secondary flow were minimized with a lengthened nozzle. The ANSYS simulation was also used to investigate the ring-vortex generation and why the ring vortex can be eliminated by adding a mask with an aperture between the nozzle and deposition substrate. The experimental results also showed that particle deposition with a lengthened nozzle was more stable, while adding the mask stabilized deposition and diminished the ring-vortex contamination. The effects of flow rate and pressure were also investigated. Hence, the deposition stability and homogeneity of microparticles was improved. Full article

(This article belongs to the Special Issue Design and Development of Nanostructured Thin Films)

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15 pages, 6257 KiB

Open AccessArticle

The Preparation of Graphene Oxide-Silver Nanocomposites: The Effect of Silver Loads on Gram-Positive and Gram-Negative Antibacterial Activities

by Truong Thi Tuong Vi¹, Selvaraj Rajesh Kumar¹

, Bishakh Rout², Chi-Hsien Liu²

, Chak-Bor Wong³, Chia-Wei Chang³, Chien-Hao Chen³, Dave W. Chen^3,* and Shingjiang Jessie Lue^1,4,5,*

¹ Department of Chemical and Materials Engineering and Green Technology Research Center, Chang Gung University, Taoyuan City 333, Taiwan

² Department of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan City 333, Taiwan

³ Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Keelung City 204, Taiwan

⁴ Department of Safety, Health and Environment Engineering, Ming-Chi University of Technology, New Taipei City 243, Taiwan

⁵ Department of Radiation Oncology, Chang Gung Memorial Hospital, Taoyuan City 333, Taiwan

Nanomaterials 2018, 8(3), 163; https://doi.org/10.3390/nano8030163 - 14 Mar 2018

Cited by 77 | Viewed by 9658

Abstract

In this work, silver nanoparticles (Ag NPs) were decorated on thiol (–SH) grafted graphene oxide (GO) layers to investigate the antibacterial activities in Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Pseudomonas aeruginosa). The quasi-spherical, nano-sized Ag NPs were attached [...] Read more.

In this work, silver nanoparticles (Ag NPs) were decorated on thiol (–SH) grafted graphene oxide (GO) layers to investigate the antibacterial activities in Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Pseudomonas aeruginosa). The quasi-spherical, nano-sized Ag NPs were attached to the GO surface layers, as confirmed by using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), respectively. The average size of GO-Ag nanocomposites was significantly reduced (327 nm) from those of pristine GO (962 nm) while the average size of loaded Ag NPs was significantly smaller than the Ag NPs without GO. Various concentrations of AgNO₃ solutions (0.1, 0.2, and 0.25 M) were loaded into GO nanosheets and resulted in the Ag contents of 31, 43, and 65%, respectively, with 1–2 nm sizes of Ag NPs anchored on the GO layers. These GO-Ag samples have negative surface charges but the GO-Ag 0.2 M sample (43% Ag) demonstrated the highest antibacterial efficiency. At 10 ppm load of GO-Ag suspension, only a GO-Ag 0.2 M sample yielded slight bacterial inhibition (5.79–7.82%). As the GO-Ag content was doubled to 20 ppm, the GO-Ag 0.2 M composite exhibited ~49% inhibition. When the GO-Ag 0.2 M composite level was raised to 100 ppm, almost 100% inhibition efficiencies were found on both Staphylococcus aureus (S.A.) and Pseudomonas aeruginosa (P.A.), which were significantly higher than using pristine GO (27% and 33% for S.A. and P.A.). The combined effect of GO and Ag nanoparticles demonstrate efficient antibacterial activities. Full article

(This article belongs to the Special Issue Antibacterial Activity of Nanomaterials)

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16 pages, 5781 KiB

Open AccessArticle

One-Step Fabrication of Dual Responsive Lignin Coated Fe₃O₄ Nanoparticles for Efficient Removal of Cationic and Anionic Dyes

by Xingang Li^1,2,3, Youyi He^1,2, Hong Sui^1,2,3 and Lin He^1,2,*

¹ School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China

² National Engineering Research Centre for Distillation Technology, Tianjin 300072, China

³ Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China

Nanomaterials 2018, 8(3), 162; https://doi.org/10.3390/nano8030162 - 14 Mar 2018

Cited by 77 | Viewed by 7749

Abstract

A new, simple one-step approach has been developed to synthesize lignin and lignin amine coated Fe₃O₄ nanoparticles. These nanoparticles (lignin magnetic nanoparticles (LMNPs) and lignin amine magnetic nanoparticles (LAMNPs)) are found to possess not only magnetic response but also pH-dependent [...] Read more.

A new, simple one-step approach has been developed to synthesize lignin and lignin amine coated Fe₃O₄ nanoparticles. These nanoparticles (lignin magnetic nanoparticles (LMNPs) and lignin amine magnetic nanoparticles (LAMNPs)) are found to possess not only magnetic response but also pH-dependent adsorption behavior. Results show that the combination of lignin with nanoparticles increased the adsorption capacities 2–5 times higher than other traditional single lignin based adsorbents (211.42 mg/g for methylene blue (MB) by LMNPs and 176.49 mg/g for acid scarlet GR (AS-GR) by LAMNPs). Meanwhile, by simply adjusting the pH, the dye-loaded adsorbents can be regenerated to recycle both adsorbents and dyes with a desorption efficiency up to 90%. Mechanistic study shows that dye structure and surface charges of adsorbents play the most important part in adsorption where dyes interact with the adsorbent surface via π–π stacking and electrostatic attraction interactions. The efficient fabrication method, eco-friendly reactant, quick magnetic separation, high adsorption and desorption efficiency suggest this novel type of nano-adsorbents to be promising materials for efficient dye pollutant removal and recovery. Full article

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15 pages, 24924 KiB

Open AccessArticle

Understanding the Effects of NaCl, NaBr and Their Mixtures on Silver Nanowire Nucleation and Growth in Terms of the Distribution of Electron Traps in Silver Halide Crystals

by Yunjun Rui^1,2,*, Weiliang Zhao¹, Dewei Zhu², Hengyu Wang¹, Guangliang Song³, Mark T. Swihart^2,*, Neng Wan⁴, Dawei Gu¹, Xiaobing Tang¹, Ying Yang¹ and Tianyou Zhang¹

¹ Department of Applied Physics, Nanjing Tech University, Nanjing 210009, China

² Department of Chemical and Biological Engineering, University at Buffalo (SUNY), Buffalo, New York, NY 14260, USA

³ College of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 210009, China

⁴ School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China

Nanomaterials 2018, 8(3), 161; https://doi.org/10.3390/nano8030161 - 14 Mar 2018

Cited by 30 | Viewed by 9152

Abstract

In recent years, many research groups have synthesized ultra-thin silver nanowires (AgNWs) with diameters below 30 nm by employing Cl⁻ and Br⁻ simultaneously in the polyol process. However, the yield of AgNWs in this method was low, due to the production [...] Read more.

In recent years, many research groups have synthesized ultra-thin silver nanowires (AgNWs) with diameters below 30 nm by employing Cl⁻ and Br⁻ simultaneously in the polyol process. However, the yield of AgNWs in this method was low, due to the production of Ag nanoparticles (AgNPs) as an unwanted byproduct, especially in the case of high Br⁻ concentration. Here, we investigated the roles of Cl⁻ and Br⁻ in the preparation of AgNWs and then synthesized high aspect ratio (up to 2100) AgNWs in high yield (>85% AgNWs) using a Cl⁻ and Br⁻ co-mediated method. We found that multiply-twinned particles (MTPs) with different critical sizes were formed and grew into AgNWs, accompanied by a small and large amount of AgNPs for the NaCl and NaBr additives, respectively. For the first time, we propose that the growth of AgNWs of different diameters and yields can be understood based on the electron trap distribution (ETD) of the silver halide crystals. For the case of Cl⁻ and Br⁻ co-additives, a mixed silver halide crystal of AgBr_1−xCl_x was formed, rather than the AgBr/AgCl mixture reported previously. In this type of crystal, the ETD is uniform, which is beneficial for the synthesis of AgNWs with small diameter (30~40 nm) and high aspect ratio. AgNW transparent electrodes were prepared in air by rod coating. A sheet resistance of 48 Ω/sq and transmittance of 95% at 550 nm were obtained without any post-treatment. Full article

(This article belongs to the Special Issue Synthesis and Characterization of Nanowires)

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29 pages, 1506 KiB

Open AccessArticle

In Vitro and In Vivo Short-Term Pulmonary Toxicity of Differently Sized Colloidal Amorphous SiO₂

by Martin Wiemann^1,*, Ursula G. Sauer², Antje Vennemann¹, Sandra Bäcker³, Johannes-Georg Keller⁴

, Lan Ma-Hock⁵, Wendel Wohlleben⁴

and Robert Landsiedel⁵

¹ IBR R&D gGmbH Institute for Lung Health, Mendelstr. 11, 48149 Münster, Germany

² Scientific Consultancy—Animal Welfare, 85579 Neubiberg, Germany

³ BASF SE, Human Biomonitoring and Industrial Hygiene, 67056 Ludwigshafen, Germany

⁴ BASF SE, Advanced Materials Research, 67056 Ludwigshafen, Germany

⁵ BASF SE, Experimental Toxicology and Ecology, 67056 Ludwigshafen, Germany

Nanomaterials 2018, 8(3), 160; https://doi.org/10.3390/nano8030160 - 13 Mar 2018

Cited by 25 | Viewed by 6257

Abstract

In vitro prediction of inflammatory lung effects of well-dispersed nanomaterials is challenging. Here, the in vitro effects of four colloidal amorphous SiO₂ nanomaterials that differed only by their primary particle size (9, 15, 30, and 55 nm) were analyzed using the rat [...] Read more.

In vitro prediction of inflammatory lung effects of well-dispersed nanomaterials is challenging. Here, the in vitro effects of four colloidal amorphous SiO₂ nanomaterials that differed only by their primary particle size (9, 15, 30, and 55 nm) were analyzed using the rat NR8383 alveolar macrophage (AM) assay. Data were compared to effects of single doses of 15 nm and 55 nm SiO₂ intratracheally instilled in rat lungs. In vitro, all four elicited the release of concentration-dependent lactate dehydrogenase, β-glucuronidase, and tumor necrosis factor alpha, and the two smaller materials also released H₂O₂. All effects were size-dependent. Since the colloidal SiO₂ remained well-dispersed in serum-free in vitro conditions, effective particle concentrations reaching the cells were estimated using different models. Evaluating the effective concentration–based in vitro effects using the Decision-making framework for the grouping and testing of nanomaterials, all four nanomaterials were assigned as “active.” This assignment and the size dependency of effects were consistent with the outcomes of intratracheal instillation studies and available short-term rat inhalation data for 15 nm SiO₂. The study confirms the applicability of the NR8383 AM assay to assessing colloidal SiO₂ but underlines the need to estimate and consider the effective concentration of such well-dispersed test materials. Full article

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13 pages, 6258 KiB

Open AccessArticle

Sustained Cytotoxicity of Wogonin on Breast Cancer Cells by Encapsulation in Solid Lipid Nanoparticles

by Jong-Suep Baek, Young-Guk Na

and Cheong-Weon Cho^*

College of Pharmacy and Institute of Drug Research and Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Korea

Nanomaterials 2018, 8(3), 159; https://doi.org/10.3390/nano8030159 - 13 Mar 2018

Cited by 55 | Viewed by 6086

Abstract

While wogonin has been known to have cytotoxicity against various cancer cells, its bioavailability and cytotoxicity are low due to its low water solubility. Therefore, wogonin-loaded solid lipid nanoparticles were fabricated using a hot-melted evaporation technique. The highest solubility of wogonin was observed [...] Read more.

While wogonin has been known to have cytotoxicity against various cancer cells, its bioavailability and cytotoxicity are low due to its low water solubility. Therefore, wogonin-loaded solid lipid nanoparticles were fabricated using a hot-melted evaporation technique. The highest solubility of wogonin was observed in stearic acid. Hence, wogonin-loaded solid lipid nanoparticles were composed of stearic acid as the lipid matrix. The physicochemical properties of the wogonin-loaded solid lipid nanoparticles were evaluated by dynamic laser scattering and scanning electron microscopy. The wogonin-loaded solid lipid nanoparticles exhibited sustained and controlled release up to 72 h. In addition, it was observed that the wogonin-loaded solid lipid nanoparticles exhibited enhanced cytotoxicity and inhibited poly (ADP-ribose) polymerase in MCF-7 breast cancer cells. Overall, the results indicate that wogonin-loaded solid lipid nanoparticles could be an efficient delivery system for the treatment of breast cancer. Full article

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13 pages, 3398 KiB

Open AccessArticle

A Comparison of the Effects of Packaging Containing Nano ZnO or Polylysine on the Microbial Purity and Texture of Cod (Gadus morhua) Fillets

by Małgorzata Mizielińska^*

, Urszula Kowalska, Michał Jarosz and Patrycja Sumińska

Center of Bioimmobilisation and Innovative Packaging Materials, Faculty of Food Sciences and Fisheries, West Pomeranian University of Technology Szczecin, Janickiego 35, 71-270 Szczecin, Poland

Nanomaterials 2018, 8(3), 158; https://doi.org/10.3390/nano8030158 - 12 Mar 2018

Cited by 43 | Viewed by 5367

Abstract

Portions of fresh Baltic cod fillets were packed into cellulose boxes (control samples), which were covered with Methyl Hydroxypropyl Celluloses (MHPC) coating with 2% polylysine. The cellulose boxes had square PE films and were enclosed in MHPC coating containing ZnO nanoparticles. The cod [...] Read more.

Portions of fresh Baltic cod fillets were packed into cellulose boxes (control samples), which were covered with Methyl Hydroxypropyl Celluloses (MHPC) coating with 2% polylysine. The cellulose boxes had square PE films and were enclosed in MHPC coating containing ZnO nanoparticles. The cod fillets were stored at 5 °C and examined after 72 h and 144 h storage times. Results obtained in this study showed that the textural parameters of the cod fillets increased, with both Springiness and Cohesiveness found greater after 144 h of storage for all analysed packaging materials. The Gumminess of fillets increased after storage, but the lowest increase was noted in cod samples that were stored in boxes containing PE films with ZnO nanoparticles. It was found that water loss from the cod fillets in these boxes was also lowest. The Adhesiveness of the fish samples stored in boxes devoid of active coatings also increased. In contrast to the packaging material devoid of active coatings, the storage of fillets in active coating boxes resulted in a decrease of adhesiveness. Microbial analysis showed that packaging material containing nano-ZnO was found to be more active against mesophilic and psychotropic bacterial cells than the coatings with polylysine after 72 h and 144 h of storage. Full article

(This article belongs to the Special Issue Antibacterial Activity of Nanomaterials)

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10 pages, 2348 KiB

Open AccessArticle

Influence of InAlN Nanospiral Structures on the Behavior of Reflected Light Polarization

by Yu-Hung Kuo, Roger Magnusson, Elena Alexandra Serban

, Per Sandström, Lars Hultman, Kenneth Järrendahl

, Jens Birch

and Ching-Lien Hsiao^*

Thin Film Physics Division, Department of Physics, Chemistry, and Biology (IFM), Linköping University, SE-581 83 Linköping, Sweden

Nanomaterials 2018, 8(3), 157; https://doi.org/10.3390/nano8030157 - 12 Mar 2018

Cited by 3 | Viewed by 4469

Abstract

The influence of structural configurations of indium aluminum nitride (InAlN) nanospirals, grown by reactive magnetron sputter epitaxy, on the transformation of light polarization are investigated in terms of varying structural chirality, growth temperatures, titanium nitride (TiN) seed (buffer) layer thickness, nanospiral thickness, and [...] Read more.

The influence of structural configurations of indium aluminum nitride (InAlN) nanospirals, grown by reactive magnetron sputter epitaxy, on the transformation of light polarization are investigated in terms of varying structural chirality, growth temperatures, titanium nitride (TiN) seed (buffer) layer thickness, nanospiral thickness, and pitch. The handedness of reflected circularly polarized light in the ultraviolet–visible region corresponding to the chirality of nanospirals is demonstrated. A high degree of circular polarization (P_c) value of 0.75 is obtained from a sample consisting of 1.2 μm InAlN nanospirals grown at 650 °C. A film-like structure is formed at temperatures lower than 450 °C. At growth temperatures higher than 750 °C, less than 0.1 In-content is incorporated into the InAlN nanospirals. Both cases reveal very low P_c. A red shift of wavelength at P_c peak is found with increasing nanospiral pitch in the range of 200–300 nm. The P_c decreases to 0.37 for two-turn nanospirals with total length of 0.7 μm, attributed to insufficient constructive interference. A branch-like structure appears on the surface when the nanospirals are grown longer than 1.2 μm, which yields a low P_c around 0.5, caused by the excessive scattering of incident light. Full article

(This article belongs to the Special Issue Design and Development of Nanostructured Thin Films)

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20 pages, 5191 KiB

Open AccessArticle

Preparation and Characterization of WS₂@SiO₂ and WS₂@PANI Core-Shell Nanocomposites

by Hagit Sade and Jean-Paul Lellouche^*

Institute of Nanotechnology and Advanced Materials & Department of Chemistry, Faculty of Exact Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel

Nanomaterials 2018, 8(3), 156; https://doi.org/10.3390/nano8030156 - 10 Mar 2018

Cited by 21 | Viewed by 7599

Abstract

Two tungsten disulfide (WS₂)-based core-shell nanocomposites were fabricated using readily available reagents and simple procedures. The surface was pre-treated with a surfactant couple in a layer-by-layer approach, enabling good dispersion of the WS₂ nanostructures in aqueous media and providing a [...] Read more.

Two tungsten disulfide (WS₂)-based core-shell nanocomposites were fabricated using readily available reagents and simple procedures. The surface was pre-treated with a surfactant couple in a layer-by-layer approach, enabling good dispersion of the WS₂ nanostructures in aqueous media and providing a template for the polymerization of a silica (SiO₂) shell. After a Stöber-like reaction, a conformal silica coating was achieved. Inspired by the resulting nanocomposite, a second one was prepared by reacting the surfactant-modified WS₂ nanostructures with aniline and an oxidizing agent in an aqueous medium. Here too, a conformal coating of polyaniline (PANI) was obtained, giving a WS₂@PANI nanocomposite. Both nanocomposites were analyzed by electron microscopy, energy dispersive X-ray spectroscopy (EDS) and FTIR, verifying the core-shell structure and the character of shells. The silica shell was amorphous and mesoporous and the surface area of the composite increases with shell thickness. Polyaniline shells slightly differ in their morphologies dependent on the acid used in the polymerization process and are amorphous like the silica shell. Electron paramagnetic resonance (EPR) spectroscopy of the WS₂@PANI nanocomposite showed variation between bulk PANI and the PANI shell. These two nanocomposites have great potential to expand the use of transition metals dichalcogenides (TMDCs) for new applications in different fields. Full article

(This article belongs to the Special Issue Nanomaterials with Functional Polymer Elements)

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13 pages, 978 KiB

Open AccessArticle

Microglial Immune Response to Low Concentrations of Combustion-Generated Nanoparticles: An In Vitro Model of Brain Health

by Cayla M. Duffy^1,2, Jacob Swanson^3,4, William Northrop⁴, Joshua P. Nixon^1,2 and Tammy A. Butterick^1,2,*

¹ Minneapolis Veterans Affairs Health Care System, Minneapolis, MN 55417, USA

² Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN 55108, USA

³ Department of Integrated Engineering, Minnesota State University, Mankato, MN 56001, USA

⁴ Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455, USA

Nanomaterials 2018, 8(3), 155; https://doi.org/10.3390/nano8030155 - 9 Mar 2018

Cited by 12 | Viewed by 4942

Abstract

The brain is the central regulator for integration and control of responses to environmental cues. Previous studies suggest that air pollution may directly impact brain health by triggering the onset of chronic neuroinflammation. We hypothesize that nanoparticle components of combustion-generated air pollution may [...] Read more.

The brain is the central regulator for integration and control of responses to environmental cues. Previous studies suggest that air pollution may directly impact brain health by triggering the onset of chronic neuroinflammation. We hypothesize that nanoparticle components of combustion-generated air pollution may underlie these effects. To test this association, a microglial in vitro biological sensor model was used for testing neuroinflammatory response caused by low-dose nanoparticle exposure. The model was first validated using 20 nm silver nanoparticles (AgNP). Next, neuroinflammatory response was tested after exposure to size-selected 20 nm combustion-generated nanoparticles (CGNP) collected from a modern diesel engine. We show that low concentrations of CGNPs promote low-grade inflammatory response indicated by increased pro-inflammatory cytokine release (tumor necrosis factor-α), similar to that observed after AgNP exposure. We also demonstrate increased production of reactive oxygen species and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65 phosphorylation in microglia after CGNP stimulation. Finally, we show conditioned media from CGNP-stimulated microglia significantly reduced hypothalamic neuronal survival in vitro. To our knowledge, this data show for the first time that exposure to AgNP and CGNP elicits microglial neuroinflammatory response through the activation of NF-κB. Full article

(This article belongs to the Special Issue Nanoparticles in Neurology)

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14 pages, 6046 KiB

Open AccessArticle

Chemical Synthesis of High-Stable Amorphous FeCo Nanoalloys with Good Magnetic Properties

by Bai Yang^*, Yue Wu, Xiaopan Li and Ronghai Yu

Key Laboratory of Aerospace Advanced Materials and Performance, Ministry of Education, School of Materials Science and Engineering, Beihang University, Beijing 100191, China

Nanomaterials 2018, 8(3), 154; https://doi.org/10.3390/nano8030154 - 9 Mar 2018

Cited by 29 | Viewed by 6346

Abstract

It is difficult to fabricate high-purity amorphous FeCo alloys by traditional physical methods due to their weak glass forming ability. In this work, the fully amorphous FeCo nanoalloys with high purity and good stability have been prepared by a direct chemical reduction of [...] Read more.

It is difficult to fabricate high-purity amorphous FeCo alloys by traditional physical methods due to their weak glass forming ability. In this work, the fully amorphous FeCo nanoalloys with high purity and good stability have been prepared by a direct chemical reduction of Fe²⁺ and Co²⁺ ions with NaBH₄ as the reducing agent and polyvinylpyrrolidone (PVP) as the surfactant. The morphologies, surface compositions and particle sizes with their distribution of these amorphous samples can be effectively tuned by the suitable PVP additions. High crystallization temperature up to 468 °C, high saturation magnetization of 196.2 A·m²·kg⁻¹ and low coercivity of 83.3 Oe are obtained in amorphous FeCo nanoalloys due to their uniform distribution, weak surface oxidation and low surface B concentration. Good frequency-dependent magnetic properties can be also achieved in the fully compacted amorphous sample with a high density of 7.20 g/cm³. The simple chemical method, high stability and good magnetic properties for these amorphous FeCo nanoalloys promise their significant potential applications in high-power magnetic devices. Full article

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14 pages, 14612 KiB

Open AccessArticle

Aqueous-Phase Hydrogenolysis of Glycerol over Re Promoted Ru Catalysts Encapuslated in Porous Silica Nanoparticles

by Kuo-Tseng Li^* and Ruey-Hsiang Yen

Department of Chemical Engineering, Tunghai University, 40704 Taichung, Taiwan

Nanomaterials 2018, 8(3), 153; https://doi.org/10.3390/nano8030153 - 9 Mar 2018

Cited by 16 | Viewed by 5837

Abstract

Activity improvement of Ru-based catalysts is needed for efficient production of valuable chemicals from glycerol hydrogenolysis. In this work, a series of Re promoted Ru catalysts encapuslated in porous silica nanoparticles (denoted as Re-Ru@SiO₂) were prepared by coating silica onto the [...] Read more.

Activity improvement of Ru-based catalysts is needed for efficient production of valuable chemicals from glycerol hydrogenolysis. In this work, a series of Re promoted Ru catalysts encapuslated in porous silica nanoparticles (denoted as Re-Ru@SiO₂) were prepared by coating silica onto the surface of chemically reduced Ru-polyvinylpyrrolidone colloids, and were used to catalyze the conversion of glycerol to diols and alcohols in water. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption, X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction (TPR) were used to characterize these nanoparticles. Effects of Ru/Si atomic ratio, Re addition, glycerol and catalyst concentrations, reaction time, temperature, and hydrogen pressure were investigated. Re addition retarded the reduction of ruthenium oxide, but increased the catalyst reactivity for glycerol hydrogenolysis. Due to its greater Ru content, Re-Ru@ SiO₂ showed much better activity (reacted at much lower temperature) and more yields of 1,2-propanediol and overall liquid-phase products than Re-Ru/SiO₂ (prepared by conventional impregnation method) reported before. The rate of glycerol disappearance exhibited first-order dependence on glycerol concentration and hydrogen pressure, with an activation energy of 107.8 kJ/mol. The rate constant increased linearly with increasing Ru/Si atomic ratio and catalyst amount. The yield of overall liquid-phase products correlated well with glycerol conversion. Full article

(This article belongs to the Special Issue Sustainable Nanoparticles - Their Synthesis and Catalytic Applications)

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12 pages, 3406 KiB

Open AccessArticle

Ultra-Fine Bubble Distributions in a Plant Factory Observed by Transmission Electron Microscope with a Freeze-Fracture Replica Technique

by Tsutomu Uchida^1,*

, Hitoshi Nishikawa², Nobuki Sakurai², Masashi Asano³ and Naoki Noda²

¹ Faculty of Engineering, Hokkaido University, Sapporo, Hokkaido 060-8628, Japan

² Minamata Research Center, JNC Co., Minamata, Kumamoto 867-8501, Japan

³ Business Promotion Office, JNC Co., Chiyoda-ku, Tokyo 100-8105, Japan

Nanomaterials 2018, 8(3), 152; https://doi.org/10.3390/nano8030152 - 8 Mar 2018

Cited by 14 | Viewed by 5991

Abstract

Water containing ultra-fine bubbles (UFB) may promote plant growth. But, as UFBs are too small to distinguish from other impurities in a nutrient solution, it is not known if UFBs survive transport from the water source to the rhizosphere. Here we use the [...] Read more.

Water containing ultra-fine bubbles (UFB) may promote plant growth. But, as UFBs are too small to distinguish from other impurities in a nutrient solution, it is not known if UFBs survive transport from the water source to the rhizosphere. Here we use the freeze-fracture replica method and a transmission electron microscope (TEM) to observe UFBs in the nutrient solutions used in a crop-growing system known as a plant factory. In this factory, TEM images taken from various points in the supply line indicate that the concentration of UFBs in the nutrient solution is conserved, starting from their addition to the nutrient solution in the buffer tank, through the peat-moss layer, all the way to the rhizosphere. Measurements also show that a thin film formed on the surface of UFBs in the nutrient solution, with greater film thickness at the rhizosphere. This film is considered to be made from the accumulation of impurities coming from solute and the peat-moss layer. Full article

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10 pages, 2550 KiB

Open AccessArticle

Transport and Field Emission Properties of MoS₂ Bilayers

by Francesca Urban^1,2

, Maurizio Passacantando³

, Filippo Giubileo²

, Laura Iemmo^1,2

and Antonio Di Bartolomeo^1,2,*

¹ Department of Physics “E.R. Caianiello”, University of Salerno, 84084 Fisciano, Italy

² CNR-SPIN Salerno, 84084 Fisciano, Italy

³ Department of Physical and Chemical Sciences, University of L’Aquila, and CNR-SPIN L’Aquila, 67100 L’Aquila, Italy

Nanomaterials 2018, 8(3), 151; https://doi.org/10.3390/nano8030151 - 8 Mar 2018

Cited by 76 | Viewed by 7235

Abstract

We report the electrical characterization and field emission properties of

{MoS}_{2}

bilayers deposited on a

{SiO}_{2} / Si

substrate. Current–voltage characteristics are measured in the back-gate transistor configuration, with

Ti

contacts patterned by electron beam lithography. We confirm the n-type character [...] Read more.

We report the electrical characterization and field emission properties of

{MoS}_{2}

bilayers deposited on a

{SiO}_{2} / Si

substrate. Current–voltage characteristics are measured in the back-gate transistor configuration, with

Ti

contacts patterned by electron beam lithography. We confirm the n-type character of as-grown

{MoS}_{2}

and we report normally-on field-effect transistors. Local characterization of field emission is performed inside a scanning electron microscope chamber with piezo-controlled tungsten tips working as the anode and the cathode. We demonstrate that an electric field of

~ 200 V / μ m

is able to extract current from the flat part of

{MoS}_{2}

bilayers, which can therefore be conveniently exploited for field emission applications even in low field enhancement configurations. We show that a Fowler–Nordheim model, modified to account for electron confinement in two-dimensional (2D) materials, fully describes the emission process. Full article

(This article belongs to the Special Issue Synthesis, Structure and Applications of 2D Nanomaterials)

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16 pages, 14478 KiB

Open AccessArticle

Electrospun Zein Fibers Incorporating Poly(glycerol sebacate) for Soft Tissue Engineering

by Lena Vogt¹, Liliana Liverani^1,*

, Judith A. Roether² and Aldo R. Boccaccini^1,*

¹ Institute of Biomaterials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg, Cauerstr. 6, 91058 Erlangen, Germany

² Institute of Polymer Materials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg, Martensstr. 7, 91058 Erlangen, Germany

Nanomaterials 2018, 8(3), 150; https://doi.org/10.3390/nano8030150 - 8 Mar 2018

Cited by 77 | Viewed by 7688

Abstract

For biomedical applications such as soft tissue engineering, plant proteins are becoming increasingly attractive. Zein, a class of prolamine proteins found in corn, offers excellent properties for application in the human body, but has inferior mechanical properties and lacks aqueous stability. In this [...] Read more.

For biomedical applications such as soft tissue engineering, plant proteins are becoming increasingly attractive. Zein, a class of prolamine proteins found in corn, offers excellent properties for application in the human body, but has inferior mechanical properties and lacks aqueous stability. In this study, electrospun scaffolds from neat zein and zein blended with prepolymer and mildly cross-linked poly(glycerol sebacate) (PGS) were fabricated. Less toxic solvents like acetic acid and ethanol were used. The morphological, physiochemical and degradation properties of the as-spun fiber mats were determined. Neat zein and zein-PGS fiber mats with high zein concentration (24 wt % and 27 wt %) showed defect-free microstructures. The average fiber diameter decreased with increasing PGS amount from 0.7 ± 0.2 µm to 0.09 ± 0.03 µm. The addition of PGS to zein resulted in a seven-fold increase in ultimate tensile strength and a four-fold increase in failure strain, whereas the Young’s Modulus did not change significantly. Degradation tests in phosphate buffered saline revealed the morphological instability of zein containing fiber mats in contact with aqueous media. Therefore, the fibers were in situ cross-linked with N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide (EDC)/N-Hydroxysuccinimide (NHS), which led to improved morphological stability in aqueous environment. The novel fibers have suitable properties for application in soft tissue engineering. Full article

(This article belongs to the Special Issue The Fabrication and Application of Nanofibers)

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Nanomaterials, Volume 8, Issue 3 (March 2018) – 51 articles

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