International Journal of Molecular Sciences

Research

Jump to: Review

10 pages, 2397 KiB

Open AccessArticle

GaAs-Based InPBi Quantum Dots for High Efficiency Super-Luminescence Diodes

by Liyao Zhang, Yuxin Song and Qian Gong

Int. J. Mol. Sci. 2019, 20(23), 6001; https://doi.org/10.3390/ijms20236001 - 28 Nov 2019

Cited by 2 | Viewed by 2382

Abstract

InPBi exhibits broad and strong photoluminescence at room temperature, and is a potential candidate for fabricating super-luminescence diodes applied in optical coherence tomography. In this paper, the strained InPBi quantum dot (QD) embedded in the AlGaAs barrier on a GaAs platform is proposed [...] Read more.

InPBi exhibits broad and strong photoluminescence at room temperature, and is a potential candidate for fabricating super-luminescence diodes applied in optical coherence tomography. In this paper, the strained InPBi quantum dot (QD) embedded in the AlGaAs barrier on a GaAs platform is proposed to enhance the light emission efficiency and further broaden the photoluminescence spectrum. The finite element method is used to calculate the strain distribution, band alignment and confined levels of InPBi QDs. The carrier recombinations between the ground states and the deep levels are systematically investigated. A high Bi content and a flat QD shape are found preferable for fabricating super-luminescence diodes with high efficiency and a broad emission spectrum. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Figure 1

14 pages, 2683 KiB

Open AccessArticle

Shielding of Hepatitis B Virus-Like Nanoparticle with Poly(2-Ethyl-2-Oxazoline)

by See Yee Fam, Chin Fei Chee, Chean Yeah Yong, Kok Lian Ho, Abdul Razak Mariatulqabtiah, Han Yih Lau and Wen Siang Tan

Int. J. Mol. Sci. 2019, 20(19), 4903; https://doi.org/10.3390/ijms20194903 - 3 Oct 2019

Cited by 4 | Viewed by 3730

Abstract

Virus-like nanoparticles (VLNPs) have been studied extensively as nanocarriers for targeted drug delivery to cancer cells. However, VLNPs have intrinsic drawbacks, in particular, potential antigenicity and immunogenicity, which hamper their clinical applications. Thus, they can be eliminated easily and rapidly by host immune [...] Read more.

Virus-like nanoparticles (VLNPs) have been studied extensively as nanocarriers for targeted drug delivery to cancer cells. However, VLNPs have intrinsic drawbacks, in particular, potential antigenicity and immunogenicity, which hamper their clinical applications. Thus, they can be eliminated easily and rapidly by host immune systems, rendering these nanoparticles ineffective for drug delivery. The aim of this study was to reduce the antigenicity of hepatitis B core antigen (HBcAg) VLNPs by shielding them with a hydrophilic polymer, poly(2-ethyl-2-oxazoline) (PEtOx). In the present study, an amine-functionalized PEtOx (PEtOx-NH₂) was synthesized using the living cationic ring-opening polymerization (CROP) technique and covalently conjugated to HBcAg VLNPs via carboxyl groups. The PEtOx-conjugated HBcAg (PEtOx-HBcAg) VLNPs were characterized with dynamic light scattering and UV-visible spectroscopy. The colloidal stability study indicated that both HBcAg and PEtOx-HBcAg VLNPs maintained their particle size in Tris-buffered saline (TBS) at human body temperature (37 °C) for at least five days. Enzyme-linked immunosorbent assays (ELISA) demonstrated that the antigenicity of PEtOx-HBcAg VLNPs reduced significantly as compared with unconjugated HBcAg VLNPs. This novel conjugation approach provides a general platform for resolving the antigenicity of VLNPs, enabling them to be developed into a variety of nanovehicles for targeted drug delivery. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Graphical abstract

30 pages, 4401 KiB

Open AccessArticle

Molecular and Supramolecular Interactions in Systems with Nitroxide-Based Radicals

by Maria Cristina Buta, Ana Maria Toader, Bogdan Frecus, Corneliu I. Oprea, Fanica Cimpoesu and Gabriela Ionita

Int. J. Mol. Sci. 2019, 20(19), 4733; https://doi.org/10.3390/ijms20194733 - 24 Sep 2019

Cited by 6 | Viewed by 3222

Abstract

Nitroxide-based radicals, having the advantage of firm chemical stability, are usable as probes in the detection of nanoscale details in the chemical environment of various multi-component systems, based on subtle variations in their electron paramagnetic resonance spectra. We propose a systematic walk through [...] Read more.

Nitroxide-based radicals, having the advantage of firm chemical stability, are usable as probes in the detection of nanoscale details in the chemical environment of various multi-component systems, based on subtle variations in their electron paramagnetic resonance spectra. We propose a systematic walk through the vast area of problems and inquires that are implied by the rationalization of solvent effects on the spectral parameters, by first-principle methods of structural chemistry. Our approach consists of using state-of-the-art procedures, like Density Functional Theory (DFT), on properly designed systems, kept at the border of idealization and chemical realism. Thus, we investigate the case of real solvent molecules intervening in different configurations between two radical molecules, in comparison with radicals taken in vacuum or having the solvent that is treated by surrogate models, such as polarization continuum approximation. In this work, we selected the dichloromethane as solvent and the prototype radicals abbreviated TEMPO ((2,2,6,6-Tetramethylpiperidin-1-yl) oxyl). In another branch of the work, we check the interaction of radicals with large toroidal molecules, β-cyclodextrin, and cucurbit[6]uril, modeling the interaction energy profile at encapsulation. The drawn synoptic view offers valuable rationales for understanding spectroscopy and energetics of nitroxide radicals in various environments, which are specific to soft chemistry. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Figure 1

15 pages, 2645 KiB

Open AccessArticle

Iron Release Profile of Silica-Modified Zero-Valent Iron NPs and Their Implication in Cancer Therapy

by Li-Xing Yang, Ya-Na Wu, Pei-Wen Wang, Wu-Chou Su and Dar-Bin Shieh

Int. J. Mol. Sci. 2019, 20(18), 4336; https://doi.org/10.3390/ijms20184336 - 4 Sep 2019

Cited by 13 | Viewed by 3834

Abstract

To evaluate the iron ion release profile of zero-valent iron (ZVI)-based nanoparticles (NPs) and their relationship with lysosomes in cancer cells, silica and mesoporous silica-coated ZVI NPs (denoted as ZVI@SiO₂ and ZVI@mSiO₂) were synthesized and characterized for the following study [...] Read more.

To evaluate the iron ion release profile of zero-valent iron (ZVI)-based nanoparticles (NPs) and their relationship with lysosomes in cancer cells, silica and mesoporous silica-coated ZVI NPs (denoted as ZVI@SiO₂ and ZVI@mSiO₂) were synthesized and characterized for the following study of cytotoxicity, intracellular iron ion release, and their underlying mechanisms. ZVI@mSiO₂ NPs showed higher cytotoxicity than ZVI@SiO₂ NPs in the OEC-M1 oral cancer cell line. In addition, internalized ZVI@mSiO₂ NPs deformed into hollow and void structures within the cells after a 24-h treatment, but ZVI@SiO₂ NPs remained intact after internalization. The intracellular iron ion release profile was also accordant with the structural deformation of ZVI@mSiO₂ NPs. Burst iron ion release occurred in ZVI@mSiO₂-treated cells within an hour with increased lysosome membrane permeability, which induced massive reactive oxygen species generation followed by necrotic and apoptotic cell death. Furthermore, inhibition of endosome–lysosome system acidification successfully compromised burst iron ion release, thereby reversing the cell fate. An in vivo test also showed a promising anticancer effect of ZVI@mSiO₂ NPs without significant weight loss. In conclusion, we demonstrated the anticancer property of ZVI@mSiO₂ NPs as well as the iron ion release profile in time course within cells, which is highly associated with the surface coating of ZVI NPs and lysosomal acidification. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Graphical abstract

11 pages, 2615 KiB

Open AccessArticle

Polyvinyl Butyral (PVB) Nanofiber/Nanoparticle-Covered Yarns for Antibacterial Textile Surfaces

by Fatma Yalcinkaya and Michal Komarek

Int. J. Mol. Sci. 2019, 20(17), 4317; https://doi.org/10.3390/ijms20174317 - 3 Sep 2019

Cited by 19 | Viewed by 4522

Abstract

In this study, nanoparticle-incorporated nanofiber-covered yarns were prepared using a custom-made needle-free electrospinning system. The ultimate goal of this work was to prepare functional nanofibrous surfaces with antibacterial properties and realize high-speed production. As antibacterial agents, we used various amounts of copper oxide [...] Read more.

In this study, nanoparticle-incorporated nanofiber-covered yarns were prepared using a custom-made needle-free electrospinning system. The ultimate goal of this work was to prepare functional nanofibrous surfaces with antibacterial properties and realize high-speed production. As antibacterial agents, we used various amounts of copper oxide (CuO) and vanadium (V) oxide (V₂O₅) nanoparticles (NPs). Three yarn preparation speeds (100 m/min, 150 m/min, and 200 m/min) were used for the nanofiber-covered yarn. The results indicate a relationship between the yarn speed, quantity of NPs, and antibacterial efficiency of the material. We found a higher yarn speed to be associated with a lower reduction in bacteria. NP-loaded nanofiber yarns were proven to have excellent antibacterial properties against Gram-negative Escherichia coli (E. coli). CuO exhibited a greater inhibition and bactericidal effect against E. coli than V₂O₅. In brief, the studied samples are good candidates for use in antibacterial textile surface applications, such as wastewater filtration. As greater attention is being drawn to this field, this work provides new insights regarding the antibacterial textile surfaces of nanofiber-covered yarns. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Graphical abstract

9 pages, 1847 KiB

Open AccessArticle

Magnetorheological Hybrid Elastomers Based on Silicone Rubber and Magnetorheological Suspensions with Graphene Nanoparticles: Effects of the Magnetic Field on the Relative Dielectric Permittivity and Electric Conductivity

by Ioan Bica and Octavian Mădălin Bunoiu

Int. J. Mol. Sci. 2019, 20(17), 4201; https://doi.org/10.3390/ijms20174201 - 27 Aug 2019

Cited by 16 | Viewed by 3078

Abstract

Hybrid magnetorheological elastomers (hMREs) were manufactured based on silicone rubber, silicone oil, carbonyl iron microparticles, graphene nanoparticles and cotton fabric. Using the hMREs, flat capacitors (FCs) were made. Using the installation described in this paper, the electrical capacitance and the coefficient of dielectric [...] Read more.

Hybrid magnetorheological elastomers (hMREs) were manufactured based on silicone rubber, silicone oil, carbonyl iron microparticles, graphene nanoparticles and cotton fabric. Using the hMREs, flat capacitors (FCs) were made. Using the installation described in this paper, the electrical capacitance and the coefficient of dielectric losses of the hMREs were measured as a function of the intensity of the magnetic field superimposed over an alternating electric field. From the data obtained, the electrical conductivity, the relative dielectric permittivity and magnetodielectric effects are determined. It is observed that the obtained quantities are significantly influenced by the intensity of the magnetic field and the amount of graphene used. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Graphical abstract

15 pages, 4181 KiB

Open AccessArticle

Preparation and Characterization of Whey Protein Isolate–DIM Nanoparticles

by Abbas Khan, Cuina Wang, Xiaomeng Sun, Adam Killpartrick and Mingruo Guo

Int. J. Mol. Sci. 2019, 20(16), 3917; https://doi.org/10.3390/ijms20163917 - 12 Aug 2019

Cited by 42 | Viewed by 5201

Abstract

3,3’-Diindolylmethane (DIM) is a bioactive compound found in Cruciferous vegetables that possesses health benefits such as antioxidant, anticancer, and anti-inflammatory effects. However, hydrophobicity and photolabile limit its pharmaceutical applications. This study aims to prepare and characterize DIM-encapsulated whey protein isolate (WPI) nanoparticles mixed [...] Read more.

3,3’-Diindolylmethane (DIM) is a bioactive compound found in Cruciferous vegetables that possesses health benefits such as antioxidant, anticancer, and anti-inflammatory effects. However, hydrophobicity and photolabile limit its pharmaceutical applications. This study aims to prepare and characterize DIM-encapsulated whey protein isolate (WPI) nanoparticles mixed at different ratios of WPI and DIM using the combined heating–ultrasound method. Results showed that all the samples showed adequate physicochemical characteristics: The mean particle size of the nanoparticles could be controlled down to 96–157 nm depending on the DIM to WPI ratio used in the preparation with a low polydispersity index (<0.5), higher negative values of zeta potential (>−40 mV) as well as with greater encapsulation efficiency (>82%). Flow behavior indices showed the shear-thinning Non-Newtonian or pseudoplastic (n < 1) behavior of the nanoparticles. The thermal properties were characterized by differential scanning calorimetry (DSC), which showed that DIM was successfully entrapped in WPI nanoparticles. The secondary structure of WPI was changed after DIM incorporation; electrostatic interaction and hydrogen bonding were major facilitating forces for nanoparticles formation, confirmed by Fourier Transform Infrared Spectroscopy (FT-IR). Transmission electron microscopy (TEM) micrographs showed that all the samples had a smooth surface and spherical structure. The wall material (WPI) and encapsulation method provide effective protection to DIM against UV light and a broad range of physiologically relevant pH’s (2.5, 3.5, 4.5, 5.5, and 7). In conclusion, whey protein isolate (WPI)-based nanoparticles are a promising approach to encapsulate DIM and overcome its physicochemical limitations with improved stability. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Figure 1

12 pages, 2709 KiB

Open AccessArticle

A Transparency Sheet-Based Colorimetric Device for Simple Determination of Calcium Ions Using Induced Aggregation of Modified Gold Nanoparticles

by Paweenar Duenchay, Orawon Chailapakul and Weena Siangproh

Int. J. Mol. Sci. 2019, 20(12), 2954; https://doi.org/10.3390/ijms20122954 - 17 Jun 2019

Cited by 8 | Viewed by 4943

Abstract

A simple and novel transparency sheet-based colorimetric detection device using gold nanoparticles (AuNPs) modified by 4-Amino-6-hydroxy-2-mercaptopyrimidine monohydrate (AHMP) was fabricated and developed for the determination of calcium ions (Ca²⁺). The detection was based on a colorimetric reaction as a result of [...] Read more.

A simple and novel transparency sheet-based colorimetric detection device using gold nanoparticles (AuNPs) modified by 4-Amino-6-hydroxy-2-mercaptopyrimidine monohydrate (AHMP) was fabricated and developed for the determination of calcium ions (Ca²⁺). The detection was based on a colorimetric reaction as a result of the aggregation of modified AuNPs induced by Ca²⁺ due to the ability to form strong electrostatic interactions between positively charged Ca²⁺ and negatively charged modified AuNPs. Probe solution changes color from red to blue in the presence of Ca²⁺ and can be observed by the naked eyes. To verify the complete self-assembly of the AHMP onto the AuNP surface, the modified AuNPs were characterized using ultraviolet–visible spectroscopy and zeta potential measurements. Under optimal conditions, a quantitative linearity was 10 to 100 ppm (R² = 0.9877) with a detection limit of 3.05 ppm. The results obtained by the developed method were in good agreement with standard atomic absorption spectrometry (AAS) results and demonstrated that this method could reliably measure Ca²⁺. Overall, this novel alternative approach presents a low-cost, simple, sensitive, rapid, and promising device for the detection of Ca²⁺. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Graphical abstract

12 pages, 7751 KiB

Open AccessArticle

New Insights into Flexible Transparent Conductive Silver Nanowires Films

by Yuehui Wang, Xing Yang, Dexi Du, Yuzhen Zhao and Xianfeng Zhang

Int. J. Mol. Sci. 2019, 20(11), 2803; https://doi.org/10.3390/ijms20112803 - 8 Jun 2019

Cited by 12 | Viewed by 3637

Abstract

Flexible transparent conductive films (FTCFs) composed of silver nanowires (AgNWs) have become an important research direction because of their potential in flexible electronic devices. The optoelectronic properties of FTCFs composed of AgNWs of different lengths were evaluated in this study. AgNWs, with an [...] Read more.

Flexible transparent conductive films (FTCFs) composed of silver nanowires (AgNWs) have become an important research direction because of their potential in flexible electronic devices. The optoelectronic properties of FTCFs composed of AgNWs of different lengths were evaluated in this study. AgNWs, with an average diameter of about 25 nm and length of 15.49–3.92 μm were obtained by a sonication-induced scission process. AgNW-FTCFs were prepared on polyethylene terephthalate substrates using a Meyer bar and then dried in the ambient environment. The sheet resistance, non-uniformity factor of the sheet resistance, the root mean square roughness, and haze of the FTCFs increased as the length of AgNWs decreased. The transmittance of the films increased slightly as the length of AgNWs increased. AgNWs with a length of 15.49 μm provided an AgNW-FTCF with excellent properties including haze of 0.95%, transmittance of 93.42%, and sheet resistance of 80.15 Ω∙sq⁻¹, without any additional post-treatment of the film. This work investigating the dependence of the optoelectronic properties of AgNW-FTCFs on AgNW length provides design guidelines for development of AgNW-FTCFs. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Figure 1

16 pages, 2334 KiB

Open AccessArticle

A Kriging Surrogate Model for Uncertainty Analysis of Graphene Based on a Finite Element Method

by Jiajia Shi, Liu Chu and Robin Braun

Int. J. Mol. Sci. 2019, 20(9), 2355; https://doi.org/10.3390/ijms20092355 - 13 May 2019

Cited by 16 | Viewed by 4318

Abstract

Due to the inevitable presence of random defects, unpredictable grain boundaries in macroscopic samples, stress concentration at clamping points, and unknown load distribution in the investigation of graphene sheets, uncertainties are crucial and challenging issues that require more exploration. The application of the [...] Read more.

Due to the inevitable presence of random defects, unpredictable grain boundaries in macroscopic samples, stress concentration at clamping points, and unknown load distribution in the investigation of graphene sheets, uncertainties are crucial and challenging issues that require more exploration. The application of the Kriging surrogate model in vibration analysis of graphene sheets is proposed in this study. The Latin hypercube sampling method effectively propagates the uncertainties in geometrical and material properties of the finite element model. The accuracy and convergence of the Kriging surrogate model are confirmed by a comparison with the reported references. The uncertainty analysis for both Zigzag and Armchair graphene sheets are compared and discussed. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Graphical abstract

12 pages, 3139 KiB

Open AccessArticle

Nanostructured SL9-CpG Lipovaccines Elicit Immune Response for the Treatment of Melanoma

by Li-Min Mu, Lei Liu, Rui Liu, Ya-Fei Du, Qian Luo, Jia-Rui Xu, Ying Xie and Wan-Liang Lu

Int. J. Mol. Sci. 2019, 20(9), 2207; https://doi.org/10.3390/ijms20092207 - 5 May 2019

Cited by 2 | Viewed by 3077

Abstract

Antigen peptides and adjuvants have been extensively investigated for cancer immunotherapy, and they are expected to elicit specific immune responses for cancer treatment. However, the anti-cancer efficacy of antigen peptide and adjuvant-based cancer vaccines has been limited due to the inefficient delivery to [...] Read more.

Antigen peptides and adjuvants have been extensively investigated for cancer immunotherapy, and they are expected to elicit specific immune responses for cancer treatment. However, the anti-cancer efficacy of antigen peptide and adjuvant-based cancer vaccines has been limited due to the inefficient delivery to draining lymph nodes after administration. Therefore, it is necessary to develop a suitable delivery system to transport antigen peptides and adjuvants. Here, we report a novel type of nanostructured lipovaccines for the treatment of melanoma by delivering antigen peptide (SL9) and oligodeoxynucleotide adjuvant (CpG) to the lymphatic vessels and to the draining lymph node. The SL9-CpG lipovaccines were characterized using dynamic laser scattering (DLS) and transmission electron microscopy (TEM). The lymph uptake, immune response elicitation and treatment effects were evaluated on melanoma-bearing C57BL/6 mice using flow cytometry (FCM), enzyme-linked immunosorbent assay (ELISA) and tumor inhibitory efficacy. The SL9-CpG lipovaccines were uniform with a nanoscale size (~70 nm), had high encapsulation efficiency, and exhibited effective lymph uptake, resulting in activation of specific cytotoxic CD8+ T cells, and release of IFN-γ, and a robust inhibition of tumor growth. Therefore, the nanostructured SL9-CpG lipovaccines offer a promising strategy for melanoma treatment. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Graphical abstract

16 pages, 1403 KiB

Open AccessArticle

The Application of Selenium and Copper Nanoparticles Modifies the Biochemical Responses of Tomato Plants under Stress by Alternaria solani

by Tomasa Quiterio-Gutiérrez, Hortensia Ortega-Ortiz, Gregorio Cadenas-Pliego, Alma Delia Hernández-Fuentes, Alberto Sandoval-Rangel, Adalberto Benavides-Mendoza, Marcelino Cabrera-de la Fuente and Antonio Juárez-Maldonado

Int. J. Mol. Sci. 2019, 20(8), 1950; https://doi.org/10.3390/ijms20081950 - 20 Apr 2019

Cited by 118 | Viewed by 8109

Abstract

Early blight is a disease that greatly affects Solanaceae, mainly damaging tomato plants, and causing significant economic losses. Although there are methods of biological control, these are very expensive and often their mode of action is slow. Due to this, there is a [...] Read more.

Early blight is a disease that greatly affects Solanaceae, mainly damaging tomato plants, and causing significant economic losses. Although there are methods of biological control, these are very expensive and often their mode of action is slow. Due to this, there is a need to use new techniques that allow a more efficient control of pathogens. Nanotechnology is a new alternative to solve these problems, allowing the creation of new tools for the treatment of diseases in plants, as well as the control of pathogens. The aim of the present investigation was to evaluate the foliar application of selenium and copper in the form of nanoparticles in a tomato crop infested by Alternaria solani. The severity of Alternaria solani, agronomic variables of the tomato crop, and the changes in the enzymatic and non-enzymatic antioxidant compounds were evaluated. The joint application of Se and Cu nanoparticles decreases the severity of this pathogen in tomato plants. Moreover, high doses generated an induction of the activity of the enzymes superoxide dismutase, ascorbate peroxidase, glutathione peroxidase (GPX) and phenylalanine ammonia lyase in the leaves, and the enzyme GPX in the fruit. Regarding non-enzymatic compounds in the leaves, chlorophyll a, b, and totals were increased, whereas vitamin C, glutathione, phenols, and flavonoids were increased in fruits. The application of nanoparticles generated beneficial effects by increasing the enzymatic and non-enzymatic compounds and decreasing the severity of Alternaria solani in tomato plants. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Figure 1

14 pages, 3340 KiB

Open AccessArticle

Gamma-Irradiation Induced Functionalization of Graphene Oxide with Organosilanes

by Kabiru Musa Aujara, Buong Woei Chieng, Nor Azowa Ibrahim, Norhazlin Zainuddin and Chantara Thevy Ratnam

Int. J. Mol. Sci. 2019, 20(8), 1910; https://doi.org/10.3390/ijms20081910 - 18 Apr 2019

Cited by 34 | Viewed by 5058

Abstract

Gamma-ray radiation was used as a clean and easy method for turning the physicochemical properties of graphene oxide (GO) in this study. Silane functionalized-GO were synthesized by chemically grafting 3-aminopropyltriethoxysilane (APTES) and 3-glycidyloxypropyltrimethoxysilane (GPTES) onto GO surface using gamma-ray irradiation. This established non-contact [...] Read more.

Gamma-ray radiation was used as a clean and easy method for turning the physicochemical properties of graphene oxide (GO) in this study. Silane functionalized-GO were synthesized by chemically grafting 3-aminopropyltriethoxysilane (APTES) and 3-glycidyloxypropyltrimethoxysilane (GPTES) onto GO surface using gamma-ray irradiation. This established non-contact process is used to create a reductive medium which is deemed simpler, purer and less harmful compared conventional chemical reduction. The resulting functionalized-GO were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), and Raman spectroscopy. The chemical interaction of silane with the GO surface was confirmed by FT-IR. X-ray diffraction reveals the change in the crystalline phases was due to surface functionalization. Surface defects of the GO due to the introduction of silane mioties was revealed by Raman spectroscopy. Thermogravimetric analysis of the functionalized-GO exhibits a multiple peaks in the temperature range of 200–650 °C which corresponds to the degradation of chemically grafted silane on the GO surface. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Figure 1

13 pages, 2429 KiB

Open AccessArticle

Synthesis, Characterization and Adsorptive Performances of a Composite Material Based on Carbon and Iron Oxide Particles

by Vasile Mînzatu, Corneliu-Mircea Davidescu, Petru Negrea, Mihaela Ciopec, Cornelia Muntean, Iosif Hulka, Cristina Paul, Adina Negrea and Narcis Duțeanu

Int. J. Mol. Sci. 2019, 20(7), 1609; https://doi.org/10.3390/ijms20071609 - 31 Mar 2019

Cited by 8 | Viewed by 3177

Abstract

The aim of this paper was to produce a new composite material based on carbon and iron oxides, starting from soluble starch and ferric chloride. The composite material was synthesized by simple thermal decomposition of a reaction mass obtained from starch and iron [...] Read more.

The aim of this paper was to produce a new composite material based on carbon and iron oxides, starting from soluble starch and ferric chloride. The composite material was synthesized by simple thermal decomposition of a reaction mass obtained from starch and iron chloride, in an inert atmosphere. Starch used as a carbon source also efficiently stabilizes the iron oxides particles obtained during the thermal decomposition. The reaction mass used for the thermal decomposition was obtained by simultaneously mixing the carbon and iron oxide precursors, without addition of any precipitation agent. The proper composite material can be obtained by rigorously adhering to the stirring time, temperature, and water quantity used during the preparation of the reaction mass, as well as the thermal regime and the controlled atmosphere used during the thermal decomposition. Synthesized materials were characterized using thermogravimetric analysis, X-Ray Diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infra-red spectroscopy (FT-IR). The performances of the obtained material were highlighted by studying their adsorbent properties and by determining the maximum adsorption capacity for arsenic removal from aqueous solutions. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Figure 1

15 pages, 2498 KiB

Open AccessArticle

In Vitro Cytotoxicity Evaluation of the Magnéli Phase Titanium Suboxides (Ti_xO_2x−1) on A549 Human Lung Cells

by Veno Kononenko and Damjana Drobne

Int. J. Mol. Sci. 2019, 20(1), 196; https://doi.org/10.3390/ijms20010196 - 8 Jan 2019

Cited by 21 | Viewed by 4393

Abstract

The use of titanium suboxides, known as Magnéli phase TiO_x, is expected to increase in the near future due to their desirable properties. In order to use Magnéli phase TiO_x nanoparticles safely, it is necessary to know how nanoparticles interact [...] Read more.

The use of titanium suboxides, known as Magnéli phase TiO_x, is expected to increase in the near future due to their desirable properties. In order to use Magnéli phase TiO_x nanoparticles safely, it is necessary to know how nanoparticles interact with biological systems. In this study, the cytotoxicity of three different Magnéli TiO_x nanoparticles was evaluated using human lung A549 cells and the results were compared with hazard data on two different TiO₂ nanoparticles whose biological interactions have already been extensively studied. After A549 cells were exposed to nanoparticles, the metabolic activity was measured by the Resazurin assay, the amount of cellular proteins was measured by the Coomassie Blue assay, and lysosomal integrity was measured by the Neutral Red Uptake assay. In order to investigate possible modes of particle actions, intracellular Ca²⁺ level, reactive oxygen species (ROS) production, and photo-oxidative disruptions of lysosomal membranes were assessed. All experiments were performed in serum-containing and in serum-deprived cell culture mediums. In addition, the photocatalytic activity of Magnéli TiO_x and TiO₂ nanoparticles was measured. The results show that Magnéli TiO_x nanoparticles increase intracellular Ca²⁺ but not ROS levels. In contrast, TiO₂ nanoparticles increase ROS levels, resulting in a higher cytotoxicity. Although Magnéli TiO_x nanoparticles showed a lower UV-A photocatalytic activity, the photo-stability of the lysosomal membranes was decreased by a greater extent, possibly due to particle accumulation inside lysosomes. We provide evidence that Magnéli TiO_x nanoparticles have lower overall biological activity when compared with the two TiO₂ formulations. However, some unique cellular interactions were detected and should be further studied in line with possible Magnéli TiO_x application. We conclude that Magnéli phase nanoparticles could be considered as low toxic material same as other forms of titanium oxide particles. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Figure 1

Review

Jump to: Research

12 pages, 1045 KiB

Open AccessReview

Current Treatment Strategies and Nanoparticle-Mediated Drug Delivery Systems for Pulmonary Arterial Hypertension

by Kazufumi Nakamura, Satoshi Akagi, Kentaro Ejiri, Masashi Yoshida, Toru Miyoshi, Norihisa Toh, Koji Nakagawa, Yoichi Takaya, Hiromi Matsubara and Hiroshi Ito

Int. J. Mol. Sci. 2019, 20(23), 5885; https://doi.org/10.3390/ijms20235885 - 23 Nov 2019

Cited by 19 | Viewed by 7443

Abstract

There are three critical pathways for the pathogenesis and progression of pulmonary arterial hypertension (PAH): the prostacyclin (prostaglandin I₂) (PGI₂), nitric oxide (NO), and endothelin pathways. The current approved drugs targeting these three pathways, including prostacyclin (PGI₂), [...] Read more.

There are three critical pathways for the pathogenesis and progression of pulmonary arterial hypertension (PAH): the prostacyclin (prostaglandin I₂) (PGI₂), nitric oxide (NO), and endothelin pathways. The current approved drugs targeting these three pathways, including prostacyclin (PGI₂), phosphodiesterase type-5 (PDE5) inhibitors, and endothelin receptor antagonists (ERAs), have been shown to be effective, however, PAH remains a severe clinical condition and the long-term survival of patients with PAH is still suboptimal. The full therapeutic abilities of available drugs are reduced by medication, patient non-compliance, and side effects. Nanoparticles are expected to address these problems by providing a novel drug delivery approach for the treatment of PAH. Drug-loaded nanoparticles for local delivery can optimize the efficacy and minimize the adverse effects of drugs. Prostacyclin (PGI₂) analogue, PDE5 inhibitors, ERA, pitavastatin, imatinib, rapamycin, fasudil, and oligonucleotides-loaded nanoparticles have been reported to be effective in animal PAH models and in vitro studies. However, the efficacy and safety of nanoparticle mediated-drug delivery systems for PAH treatment in humans are unknown and further clinical studies are required to clarify these points. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Figure 1

17 pages, 2771 KiB

Open AccessReview

Melt Electrospinning Designs for Nanofiber Fabrication for Different Applications

by Yasseen S. Ibrahim, Essraa A. Hussein, Moustafa M. Zagho, Ghada G. Abdo and Ahmed A. Elzatahry

Int. J. Mol. Sci. 2019, 20(10), 2455; https://doi.org/10.3390/ijms20102455 - 17 May 2019

Cited by 48 | Viewed by 6929

Abstract

Nanofibers have been attracting growing attention owing to their outstanding physicochemical and structural properties as well as diverse and intriguing applications. Electrospinning has been known as a simple, flexible, and multipurpose technique for the fabrication of submicro scale fibers. Throughout the last two [...] Read more.

Nanofibers have been attracting growing attention owing to their outstanding physicochemical and structural properties as well as diverse and intriguing applications. Electrospinning has been known as a simple, flexible, and multipurpose technique for the fabrication of submicro scale fibers. Throughout the last two decades, numerous investigations have focused on the employment of electrospinning techniques to improve the characteristics of fabricated fibers. This review highlights the state of the art of melt electrospinning and clarifies the major categories based on multitemperature control, gas assist, laser melt, coaxial, and needleless designs. In addition, we represent the effect of melt electrospinning process parameters on the properties of produced fibers. Finally, this review summarizes the challenges and obstacles connected to the melt electrospinning technique. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Figure 1

18 pages, 3836 KiB

Open AccessReview

Self-Assembly of Metal Nanoclusters for Aggregation-Induced Emission

by Jianxing Wang, Xiangfang Lin, Tong Shu, Lei Su, Feng Liang and Xueji Zhang

Int. J. Mol. Sci. 2019, 20(8), 1891; https://doi.org/10.3390/ijms20081891 - 17 Apr 2019

Cited by 48 | Viewed by 5627

Abstract

Aggregation-induced emission (AIE) is an intriguing strategy to enhance the luminescence of metal nanoclusters (NCs). However, the morphologies of aggregated NCs are often irregular and inhomogeneous, leading to instability and poor color purity of the aggregations, which greatly limit their further potential in [...] Read more.

Aggregation-induced emission (AIE) is an intriguing strategy to enhance the luminescence of metal nanoclusters (NCs). However, the morphologies of aggregated NCs are often irregular and inhomogeneous, leading to instability and poor color purity of the aggregations, which greatly limit their further potential in optical applications. Inspired by self-assembly techniques, manipulating metal NCs into well-defined architectures has achieved success. The self-assembled metal NCs often exhibit enhancing emission stability and intensity compared to the individually or randomly aggregated ones. Meanwhile, the emission color of metal NCs becomes tunable. In this review, we summarize the synthetic strategies involved in self-assembly of metal NCs for the first time. For each synthetic strategy, we describe the self-assembly mechanisms involved and the dependence of optical properties on the self-assembly. Finally, we outline the current challenges to and perspectives on the development of this area. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Figure 1

18 pages, 1227 KiB

Open AccessReview

Prevention of Deficit in Neuropsychiatric Disorders through Monitoring of Arsenic and Its Derivatives as Well as Through Bioinformatics and Cheminformatics

by Speranta Avram, Ana Maria Udrea, Adina Negrea, Mihaela Ciopec, Narcis Duteanu, Carmen Postolache, Corina Duda-Seiman, Daniel Duda-Seiman and Sergey Shaposhnikov

Int. J. Mol. Sci. 2019, 20(8), 1804; https://doi.org/10.3390/ijms20081804 - 12 Apr 2019

Cited by 10 | Viewed by 3764

Abstract

Neuropsychiatric disorders are induced by various risk factors, including direct exposure to environmental chemicals. Arsenic exposure induces neurodegeneration and severe psychiatric disorders, but the molecular mechanisms by which brain damage is induced are not yet elucidated. Our aim is to better understand the [...] Read more.

Neuropsychiatric disorders are induced by various risk factors, including direct exposure to environmental chemicals. Arsenic exposure induces neurodegeneration and severe psychiatric disorders, but the molecular mechanisms by which brain damage is induced are not yet elucidated. Our aim is to better understand the molecular mechanisms of arsenic toxicity in the brain and to elucidate possible ways to prevent arsenic neurotoxicity, by reviewing significant experimental, bioinformatics, and cheminformatics studies. Brain damage induced by arsenic exposure is discussed taking in account: the correlation between neuropsychiatric disorders and the presence of arsenic and its derivatives in the brain; possible molecular mechanisms by which arsenic induces disturbances of cognitive and behavioral human functions; and arsenic influence during psychiatric treatments. Additionally, we present bioinformatics and cheminformatics tools used for studying brain toxicity of arsenic and its derivatives, new nanoparticles used as arsenic delivery systems into the human body, and experimental ways to prevent arsenic contamination by its removal from water. The main aim of the present paper is to correlate bioinformatics, cheminformatics, and experimental information on the molecular mechanism of cerebral damage induced by exposure to arsenic, and to elucidate more efficient methods used to reduce its toxicity in real groundwater. Full article

(This article belongs to the Special Issue Nano-Materials and Methods)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Nano-Materials and Methods

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Related Special Issue

Published Papers (19 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI