[go: up one dir, main page]

Next Issue
Volume 6, May
Previous Issue
Volume 6, March
 
 

Nanomaterials, Volume 6, Issue 4 (April 2016) – 26 articles

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Section
Select all
Export citation of selected articles as:
4375 KiB  
Article
The Influence of Fluorination on Nano-Scale Phase Separation and Photovoltaic Performance of Small Molecular/PC71BM Blends
by Zhen Lu, Wen Liu, Jingjing Li, Tao Fang, Wanning Li, Jicheng Zhang, Feng Feng and Wenhua Li
Nanomaterials 2016, 6(4), 80; https://doi.org/10.3390/nano6040080 - 21 Apr 2016
Cited by 6 | Viewed by 5935
Abstract
To investigate the fluorination influence on the photovoltaic performance of small molecular based organic solar cells (OSCs), six small molecules based on 2,1,3-benzothiadiazole (BT), and diketopyrrolopyrrole (DPP) as core and fluorinated phenyl (DFP) and triphenyl amine (TPA) as different terminal units (DFP-BT-DFP, DFP-BT-TPA, [...] Read more.
To investigate the fluorination influence on the photovoltaic performance of small molecular based organic solar cells (OSCs), six small molecules based on 2,1,3-benzothiadiazole (BT), and diketopyrrolopyrrole (DPP) as core and fluorinated phenyl (DFP) and triphenyl amine (TPA) as different terminal units (DFP-BT-DFP, DFP-BT-TPA, TPA-BT-TPA, DFP-DPP-DFP, DFP-DPP-TPA, and TPA-DPP-TPA) were synthesized. With one or two fluorinated phenyl as the end group(s), HOMO level of BT and DPP based small molecular donors were gradually decreased, inducing high open circuit voltage for fluorinated phenyl based OSCs. DFP-BT-TPA and DFP-DPP-TPA based blend films both displayed stronger nano-scale aggregation in comparison to TPA-BT-TPA and TPA-DPP-TPA, respectively, which would also lead to higher hole motilities in devices. Ultimately, improved power conversion efficiency (PCE) of 2.17% and 1.22% was acquired for DFP-BT-TPA and DFP-DPP-TPA based devices, respectively. These results demonstrated that the nano-scale aggregation size of small molecules in photovoltaic devices could be significantly enhanced by introducing a fluorine atom at the donor unit of small molecules, which will provide understanding about the relationship of chemical structure and nano-scale phase separation in OSCs. Full article
(This article belongs to the Special Issue Nanostructured Solar Cells)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Normalized ultraviolet-visible spectroscopy (UV-VIS) absorption spectra of the six small molecules. (<b>a</b>,<b>c</b>) in dilute chlorobenzene (CB) solution; (<b>b</b>,<b>d</b>) as thin film on a quartz substrate.</p>
Full article ">Figure 2
<p>Cyclic voltammograms of small molecules. (<b>a</b>) DFP-BT-DFP, DFP-BT-TPA, TPA-BT-TPA; and (<b>b</b>) DFP-DPP-DFP, DFP-DPP-TPA, TPA-DPP-TPA.</p>
Full article ">Figure 3
<p><span class="html-italic">J</span>-<span class="html-italic">V</span> characteristics (<b>a</b>) and external quantum efficiencie (EQE) curves (<b>b</b>) of devices fabricated from the blend of small molecule: PC<sub>71</sub>BM.</p>
Full article ">Figure 4
<p>Atomic force microscopy (AFM) (5 × 5 μm<sup>2</sup>) height images of blend films. (<b>a</b>) TPA-BT-TPA:PC<sub>71</sub>BM; (<b>b</b>) DFP-BT-TPA:PC<sub>71</sub>BM; (<b>c</b>) TPA-DPP-TPA:PC<sub>71</sub>BM; and (<b>d</b>) DFP-DPP-TPA:PC<sub>71</sub>BM.</p>
Full article ">Figure 4 Cont.
<p>Atomic force microscopy (AFM) (5 × 5 μm<sup>2</sup>) height images of blend films. (<b>a</b>) TPA-BT-TPA:PC<sub>71</sub>BM; (<b>b</b>) DFP-BT-TPA:PC<sub>71</sub>BM; (<b>c</b>) TPA-DPP-TPA:PC<sub>71</sub>BM; and (<b>d</b>) DFP-DPP-TPA:PC<sub>71</sub>BM.</p>
Full article ">Chart 1
<p>Chemical structures of small molecules (DFP-BT-DFP, DFP-BT-TPA, TPA-BT-TPA, DFP-DPP-DFP, DFP-DPP-TPA, and TPA-DPP-TPA). DFP: fluorinated phenyl; BT: 2,1,3-benzothiadiazole; DPP: diketopyrrolopyrrole; TPA: triphenyl amine.</p>
Full article ">Scheme 1
<p>Synthetic route of six small molecules (DFP-BT-DFP, DFP-BT-TPA, TPA-BT-TPA, DFP-DPP-DFP, DFP-DPP-TPA, and TPA-DPP-TPA).</p>
Full article ">
4533 KiB  
Article
Synergistic Effect of Functionalized Nanokaolin Decorated MWCNTs on the Performance of Cellulose Acetate (CA) Membranes Spectacular
by Amina Afzal, Muhammad Shahid Rafique, Nadeem Iqbal, Asif Ali Qaiser, Abdul Waheed Anwar and Sadia Sagar Iqbal
Nanomaterials 2016, 6(4), 79; https://doi.org/10.3390/nano6040079 - 21 Apr 2016
Cited by 13 | Viewed by 5869
Abstract
In order to enhance salt rejection level and high pressure mechanical integrity, functionalized nanokaolin decorated multiwall carbon nanotubes (FNKM, 0–5 wt % loading) were incorporated into a cellulose acetate (CA) matrix using high temperature solution mixing methodology. Scanning electron microscopy (SEM), X-ray diffraction [...] Read more.
In order to enhance salt rejection level and high pressure mechanical integrity, functionalized nanokaolin decorated multiwall carbon nanotubes (FNKM, 0–5 wt % loading) were incorporated into a cellulose acetate (CA) matrix using high temperature solution mixing methodology. Scanning electron microscopy (SEM), X-ray diffraction technique (XRD), thermo-gravimetric analyzer (TGA) and Fourier transform infrared spectrometer (FTIR) were used to characterize the prepared membranes. The obtained results revealed that with increasing FNKM concentration in the host polymeric matrix, composite membrane’s structural, functional, thermal, water permeation/flux and salt rejection characteristics were also modified accordingly. Percent enhancement in salt rejection was increased around threefold by adding 5 wt % FNKM in CA. Full article
(This article belongs to the Special Issue Recent Advances in Nanomaterials’ Research: Selection from ICSSP'15)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Scanning electron microscopy (SEM) images of cellulose acetate (CA) membranes with 0–5 wt % loading of FNKM (functionalized nanokaolin decorated multiwall carbon nanotubes).</p>
Full article ">Figure 2
<p>Correlation between FNKM content (%) loading in CA membranes and average (avg.) pore size.</p>
Full article ">Figure 3
<p>Fourier transform infrared spectrometer (FTIR) spectra of FNKM, 0 and 5 wt % FNKM loaded CA membranes.</p>
Full article ">Figure 4
<p>Thermo-gravimetric analyzer (TGA) curves of (<b>a</b>) FNKM and 0–5 wt % FNKM loaded CA membranes; (<b>b</b>) magnified image of span 4 at temperature rising rate of 10 °C/min in oxygen environment.</p>
Full article ">Figure 5
<p>Differential thermal gravimetric (DTG) curves of 0–5 wt % loaded FNKM in CA membranes.</p>
Full article ">Figure 6
<p>X-ray diffraction (XRD) pattern of 0, 1, 3, 5 wt % FNKM loaded CA membranes.</p>
Full article ">Figure 7
<p>Relationship between FNKM loading content and applied pressure.</p>
Full article ">Figure 8
<p>Correlation between FNKM loading contents and flux.</p>
Full article ">Figure 9
<p>Correlation between FNKM loading content and salt rejection.</p>
Full article ">Figure 10
<p>Correlation between FNKM loading content and time taken to collect 100mL permeate.</p>
Full article ">Figure 11
<p>Schematic for experimental setup used for permeation and salt rejection tests. The image includes: N<sub>2</sub> gas cylinder (<b>1</b>); opening valve (<b>2</b>); pressure regulator (<b>3</b>); pressure gauges (<b>4</b>, <b>5</b> and <b>7</b>); gas release valve (<b>6</b>); gas valve towards cylinder (<b>8</b>); gas purge to outside (<b>9</b>); permeation module (<b>10</b>); membrane holder (<b>11</b>); permeation outlet (<b>12</b>); and volumetric container (<b>13</b>).</p>
Full article ">
2069 KiB  
Article
Cytotoxic Induction and Photoacoustic Imaging of Breast Cancer Cells Using Astaxanthin-Reduced Gold Nanoparticles
by Subramaniyan Bharathiraja, Panchanathan Manivasagan, Nhat Quang Bui, Yun-Ok Oh, In Gweon Lim, Suhyun Park and Junghwan Oh
Nanomaterials 2016, 6(4), 78; https://doi.org/10.3390/nano6040078 - 20 Apr 2016
Cited by 27 | Viewed by 7404
Abstract
Astaxanthin, a kind of photosynthetic pigment, was employed for gold nanoparticle formation. Nanoparticles were characterized using Ulteraviolet-Visible (UV-Vis) spectroscopy, transmission electron microscopy, and X-ray diffraction, and the possible presence of astaxanthin functional groups were analyzed by Fourier transform infrared spectroscopy (FTIR). The cytotoxic [...] Read more.
Astaxanthin, a kind of photosynthetic pigment, was employed for gold nanoparticle formation. Nanoparticles were characterized using Ulteraviolet-Visible (UV-Vis) spectroscopy, transmission electron microscopy, and X-ray diffraction, and the possible presence of astaxanthin functional groups were analyzed by Fourier transform infrared spectroscopy (FTIR). The cytotoxic effect of synthesized nanoparticles was evaluated against MDA-MB-231 (human breast cancer cells) using a tetrazolium-based assay, and synthesized nanoparticles exhibited dose-dependent toxicity. The morphology upon cell death was differentiated through fluorescent microscopy using different stains that predicted apoptosis. The synthesized nanoparticles were applied in ultrasound-coupled photoacoustic imaging to obtain good images of treated cells. Astaxanthin-reduced gold nanoparticle has the potential to act as a promising agent in the field of photo-based diagnosis and therapy. Full article
(This article belongs to the Special Issue Nanomaterials for Cancer Therapies)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>(<b>A</b>) Ulteraviolet-Visible spectrum of astaxanthin-reduced gold nanoparticles (Atx-AuNPs); (<b>B</b>) size distribution of Atx-AuNPs; (<b>C</b>) the topography of Atx-AuNPs represents major triangular and spherical shapes from the transmission electron microscopy (TEM) imaging. a.u.: absorbance units.</p>
Full article ">Figure 2
<p>(<b>A</b>) Fourier transform infrared spectroscopy (FTIR) spectral analysis of astaxanthin and Atx-AuNPs; (<b>B</b>) The X-ray diffraction (XRD) pattern of Atx-AuNPs exhibits a strong Au signal.</p>
Full article ">Figure 3
<p>The 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay experiment was performed in triplicate and the final values were represented as the mean ± standard deviation (SD). Legend: * = <span class="html-italic">p</span> &lt; 0.05, ** = <span class="html-italic">p</span> &lt; 0.01.</p>
Full article ">Figure 4
<p>Bright field images of control and treated Human breast cancer cell line (MDA-MB-231 cells) (<b>A</b>). Fluorescence microscopy analysis of cell death using Acridine orange-Ethidium bromide (<b>B</b>); Hoechst (<b>C</b>); and Propidium iodide (<b>D</b>) stains. Arrows indicate the apoptotic cell morphology and the dashed arrow indicates necrotic cell death.</p>
Full article ">Figure 5
<p>(<b>A</b>) Technical drawing of photoacoustic imaging system; (<b>B</b>) photograph of tissue-mimicking phantom; (<b>C</b>) maximum intensity projection (MIP) image and (<b>D</b>) 3 dimensional images of Atx-AuNPs-treated cells. Nd-YAG: neodymium-doped yttrium aluminium garnet; OPO: optical parametric oscillator; DAQ: data acquisition.</p>
Full article ">
1976 KiB  
Article
Photosensitizer-Embedded Polyacrylonitrile Nanofibers as Antimicrobial Non-Woven Textile
by Sarah L. Stanley, Frank Scholle, Jiadeng Zhu, Yao Lu, Xiangwu Zhang, Xingci Situ and Reza A. Ghiladi
Nanomaterials 2016, 6(4), 77; https://doi.org/10.3390/nano6040077 - 20 Apr 2016
Cited by 53 | Viewed by 7112
Abstract
Toward the objective of developing platform technologies for anti-infective materials based upon photodynamic inactivation, we employed electrospinning to prepare a non-woven textile comprised of polyacrylonitrile nanofibers embedded with a porphyrin-based cationic photosensitizer; termed PAN-Por(+). Photosensitizer loading was determined to be 34.8 [...] Read more.
Toward the objective of developing platform technologies for anti-infective materials based upon photodynamic inactivation, we employed electrospinning to prepare a non-woven textile comprised of polyacrylonitrile nanofibers embedded with a porphyrin-based cationic photosensitizer; termed PAN-Por(+). Photosensitizer loading was determined to be 34.8 nmol/mg material; with thermostability to 300 °C. Antibacterial efficacy was evaluated against four bacteria belonging to the ESKAPE family of pathogens (Staphylococcus aureus; vancomycin-resistant Enterococcus faecium; Acinetobacter baumannii; and Klebsiella pneumonia), as well as Escherichia coli. Our results demonstrated broad photodynamic inactivation of all bacterial strains studied upon illumination (30 min; 65 ± 5 mW/cm2; 400–700 nm) by a minimum of 99.9996+% (5.8 log units) regardless of taxonomic classification. PAN-Por(+) also inactivated human adenovirus-5 (~99.8% reduction in PFU/mL) and vesicular stomatitis virus (>7 log units reduction in PFU/mL). When compared to cellulose-based materials employing this same photosensitizer; the higher levels of photodynamic inactivation achieved here with PAN-Por(+) are likely due to the combined effects of higher photosensitizer loading and a greater surface area imparted by the use of nanofibers. These results demonstrate the potential of photosensitizer-embedded polyacrylonitrile nanofibers to serve as scalable scaffolds for anti-infective or self-sterilizing materials against both bacteria and viruses when employing a photodynamic inactivation mode of action. Full article
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Electrospinning schematic (<b>left</b>), PAN-Por<sup>(+)</sup> (<b>middle</b>), and scanning electron microscopy (SEM) images (<b>right</b>).</p>
Full article ">Figure 2
<p>Photodynamic inactivation studies employing PAN-Por<sup>(+)</sup>. (<b>A</b>) Gram-positive species: methicillin-susceptible <span class="html-italic">S. aureus</span> (MSSA) ATCC-2913 and the vancomycin-resistant <span class="html-italic">E. faecium</span> (VRE) ATCC-2320 strain. (<b>B</b>) Gram-negative species: <span class="html-italic">E. coli</span> BL21-(Dε3)pLysS, <span class="html-italic">K. pneumoniae</span> ATCC-2146, and <span class="html-italic">A. baumannii</span> ATCC-19606. For both panels, displayed are the material-free (cells-only) dark control set to 100% (black), as well as the dark control of PAN-Por<sup>(+)</sup> (maroon) and the illuminated PAN-Por<sup>(+)</sup> (red) studies, both as the percent survival of the material-free (cells-only) dark control. For all bacteria, the illumination conditions were as follows: 30 min, 400–700 nm, 65 ± 5 mW/cm<sup>2</sup> (total fluence of 118 J/cm<sup>2</sup>). As the plating technique employed to determine % survival did not allow for detection of survival rates of &lt;0.0001%, data points below the detection limit were set to 0.0001% survival for graphing purposes and are indicated by the grey shaded area. In the cases where error bars cannot be visualized, the error bars themselves were smaller than the marker employed in the plot.</p>
Full article ">Figure 3
<p>Photodynamic inactivation of <span class="html-italic">Klebsiella pneumoniae</span> using 50 nM Por<sup>(+)</sup> demonstrating that this photosensitizer (PS) concentration was unable to photoinactivate the bacterium. Displayed are the dark PS-free (cells-only) control set to 100% (black), the % survival of the dark control of Por<sup>(+)</sup> as a percent of the dark PS-free control (dark grey), the illuminated PS-free control as a percent of the dark PS-free control (light grey), and the illuminated Por<sup>(+)</sup> as a percent of the dark PS-free control (red). The illumination conditions and error bar visualizations were as described in <a href="#nanomaterials-06-00077-f002" class="html-fig">Figure 2</a>.</p>
Full article ">Figure 4
<p>Antiviral photodynamic inactivation studies employing PAN-Por<sup>(+)</sup> against (<b>A</b>) human adenovirus-5 (HAd-5) and (<b>B</b>) vesicular stomatitis virus (VSV). The black and red bars represent the number of PFU/mL of the non-illuminated (dark) and illuminated conditions, respectively, for the material-free (control), photosensitizer-free (PAN only) control, and PAN-Por<sup>(+)</sup> studies. The illumination conditions and error bar visualizations were as described in <a href="#nanomaterials-06-00077-f002" class="html-fig">Figure 2</a>.</p>
Full article ">
2131 KiB  
Review
Multifunctional Inorganic Nanoparticles: Recent Progress in Thermal Therapy and Imaging
by Kondareddy Cherukula, Kamali Manickavasagam Lekshmi, Saji Uthaman, Kihyun Cho, Chong-Su Cho and In-Kyu Park
Nanomaterials 2016, 6(4), 76; https://doi.org/10.3390/nano6040076 - 18 Apr 2016
Cited by 103 | Viewed by 11003
Abstract
Nanotechnology has enabled the development of many alternative anti-cancer approaches, such as thermal therapies, which cause minimal damage to healthy cells. Current challenges in cancer treatment are the identification of the diseased area and its efficient treatment without generating many side effects. Image-guided [...] Read more.
Nanotechnology has enabled the development of many alternative anti-cancer approaches, such as thermal therapies, which cause minimal damage to healthy cells. Current challenges in cancer treatment are the identification of the diseased area and its efficient treatment without generating many side effects. Image-guided therapies can be a useful tool to diagnose and treat the diseased tissue and they offer therapy and imaging using a single nanostructure. The present review mainly focuses on recent advances in the field of thermal therapy and imaging integrated with multifunctional inorganic nanoparticles. The main heating sources for heat-induced therapies are the surface plasmon resonance (SPR) in the near infrared region and alternating magnetic fields (AMFs). The different families of inorganic nanoparticles employed for SPR- and AMF-based thermal therapies and imaging are described. Furthermore, inorganic nanomaterials developed for multimodal therapies with different and multi-imaging modalities are presented in detail. Finally, relevant clinical perspectives and the future scope of inorganic nanoparticles in image-guided therapies are discussed. Full article
(This article belongs to the Special Issue Nanoparticles in Bioimaging)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Scheme illustrating the potential of inorganic nanoparticles in heat-induced therapies and imaging. US: ultrasound; MR: magnetic resonance; CT: computed tomography; QD: quantum dot; UCNP: upconversion nanoparticles; CuS: copper sulfide; CNT: carbon nanotube; AMF: alternate magnetic field; ROS: reactive oxygen species.</p>
Full article ">Figure 2
<p><span class="html-italic">In vitro</span> and <span class="html-italic">in vivo</span> micro-CT images: (<b>A</b>) concentration-dependent CT images of air, distilled water, and doxorubicin-loaded hollow gold nanoparticles (Dox-HGNPs); (<b>B</b>) X-ray absorption of Dox-HGNP and Ultravist 300; (<b>C</b>) cross-sectional CT image in the back skin of mice after injection of Dox-HGNPs; and (<b>D</b>) Ultravist 300. Reproduced with permission from [<a href="#B51-nanomaterials-06-00076" class="html-bibr">51</a>]. Copyright Journal of Controlled Release, Elsevier, 2015.</p>
Full article ">Figure 3
<p><span class="html-italic">In vivo</span> multispectral optoacoustic tomography (MSOT) imaging. (<b>a</b>–<b>e</b>) MSOT images of tumor before and after intravenous injection with Bi<sub>2</sub>S<sub>3</sub> nanorods (NRs); and (<b>f</b>) photoacoustic signal intensity in tumor at different time points. Reproduced with permission from [<a href="#B105-nanomaterials-06-00076" class="html-bibr">105</a>]. Copyright American Chemical Society, 2015.</p>
Full article ">Figure 4
<p>(<b>A</b>) Thermal images acquired after the intratumoral injection of nanocubes and the application of magnetic hyperthermia (MHT), near-infrared (NIR)-laser irradiation, or dual-mode treatment (both effects); (<b>B</b>) thermal elevation curves for the non-injected tumor in the dual condition; (<b>C</b>) average final temperature increase obtained on day 0 (1h after injection) and one and two days after injection for non-injected tumors; and (<b>D</b>) average tumor growth in nanocube-injected mice. Reproduced with permission from [<a href="#B143-nanomaterials-06-00076" class="html-bibr">143</a>]. Copyright American Chemical Society, 2015.</p>
Full article ">Figure 5
<p>Multimodal <span class="html-italic">in vivo</span> imaging of quantum rattles (QRs): (<b>A</b>) NIR fluorescent intensity in the areas where QRs (red) and non-fluorescent hollow mesoporous silica shells (HS) control (blue); (<b>B</b>) MR image obtained following the injection of QRs; and 3D photoacoustic images of tumors acquired at 670 nm before (<b>C</b>) and after (<b>D</b>) the injection of QRs. Reproduced with permission from [<a href="#B191-nanomaterials-06-00076" class="html-bibr">191</a>]. Copyright Proceedings of the National Academy of Sciences of the United States of America, 2015.</p>
Full article ">
3421 KiB  
Article
Temperature-Dependent Magnetic Response of Antiferromagnetic Doping in Cobalt Ferrite Nanostructures
by Adeela Nairan, Maaz Khan, Usman Khan, Munawar Iqbal, Saira Riaz and Shahzad Naseem
Nanomaterials 2016, 6(4), 73; https://doi.org/10.3390/nano6040073 - 18 Apr 2016
Cited by 70 | Viewed by 7103
Abstract
In this work MnxCo1−xFe2O4 nanoparticles (NPs) were synthesized using a chemical co-precipitation method. Phase purity and structural analyses of synthesized NPs were performed by X-ray diffractometer (XRD). Transmission electron microscopy (TEM) reveals the presence of [...] Read more.
In this work MnxCo1−xFe2O4 nanoparticles (NPs) were synthesized using a chemical co-precipitation method. Phase purity and structural analyses of synthesized NPs were performed by X-ray diffractometer (XRD). Transmission electron microscopy (TEM) reveals the presence of highly crystalline and narrowly-dispersed NPs with average diameter of 14 nm. The Fourier transform infrared (FTIR) spectrum was measured in the range of 400–4000 cm−1 which confirmed the formation of vibrational frequency bands associated with the entire spinel structure. Temperature-dependent magnetic properties in anti-ferromagnet (AFM) and ferromagnet (FM) structure were investigated with the aid of a physical property measurement system (PPMS). It was observed that magnetic interactions between the AFM (Mn) and FM (CoFe2O4) material arise below the Neel temperature of the dopant. Furthermore, hysteresis response was clearly pronounced for the enhancement in magnetic parameters by varying temperature towards absolute zero. It is shown that magnetic properties have been tuned as a function of temperature and an externally-applied field. Full article
(This article belongs to the Special Issue Recent Advances in Nanomaterials’ Research: Selection from ICSSP'15)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>X-ray diffraction (XRD) pattern for spinel Co<sub>0.8</sub>Mn<sub>0.2</sub>Fe<sub>2</sub>O<sub>4</sub> (CMF) nanoparticles (NPs).</p>
Full article ">Figure 2
<p>Transmission electron microscopy (TEM) images showing (<b>a</b>) spherical CMF NPs, whereas inset corresponds to selected area electron diffraction (SAED) pattern of NPs and (<b>b</b>) high resolution TEM (HRTEM) of single nanoparticle and insets belong to inverse fast Fourier transformation (IFFT) with interplanar distances of two regions of the twin boundary.</p>
Full article ">Figure 3
<p>Energy dispersive X-ray spectroscopy (EDS) spectrum of spinel CMF NPs.</p>
Full article ">Figure 4
<p>FTIR spectrum of CMF NPs taken in the range from 400 to 4000 cm<sup>−1</sup>.</p>
Full article ">Figure 5
<p>Zero field cooled-field cooled (ZFC-FC) curves of CMF at <span class="html-italic">H</span> = (<b>a</b>) 1kOe; (<b>b</b>) 5kOe; and (<b>c</b>) 10kOe.</p>
Full article ">Figure 6
<p>(<b>a</b>) Magnetic hysteresis loops of CMF NPs showing ferromagnetic and wasp-waist shape, taken at various temperatures ranging from 5 to 300 K and (<b>b</b>) extended view of coercivity near the origin.</p>
Full article ">Figure 7
<p>Effect of temperature on coercivity (right side) and saturation magnetization (left side) of CMF NPs.</p>
Full article ">
6068 KiB  
Article
Versatile Production of Poly(Epsilon-Caprolactone) Fibers by Electrospinning Using Benign Solvents
by Liliana Liverani and Aldo R. Boccaccini
Nanomaterials 2016, 6(4), 75; https://doi.org/10.3390/nano6040075 - 15 Apr 2016
Cited by 107 | Viewed by 9542
Abstract
The electrospinning technique is widely used for the fabrication of micro- and nanofibrous structures. Recent studies have focused on the use of less toxic and harmful solvents (benign solvents) for electrospinning, even if those solvents usually require an accurate and longer process of [...] Read more.
The electrospinning technique is widely used for the fabrication of micro- and nanofibrous structures. Recent studies have focused on the use of less toxic and harmful solvents (benign solvents) for electrospinning, even if those solvents usually require an accurate and longer process of optimization. The aim of the present work is to demonstrate the versatility of the use of benign solvents, like acetic acid and formic acid, for the fabrication of microfibrous and nanofibrous electrospun poly(epsilon-caprolactone) mats. The solvent systems were also shown to be suitable for the fabrication of electrospun structures with macroporosity, as well as for the fabrication of composite electrospun mats, fabricated by the addition of bioactive glass (45S5 composition) particles in the polymeric solution. Full article
(This article belongs to the Special Issue Nanomaterials for Tissue Engineering)
Show Figures

Figure 1

Figure 1
<p>Scanning electron microscopy (SEM) micrographs of electrospun poly(epsilon-caprolactone) (PCL) mats obtained from different PCL solutions in acetic acid (scale bar 20 μm): (<b>A</b>) 12% <span class="html-italic">w</span>/<span class="html-italic">v</span>; (<b>B</b>) 15% <span class="html-italic">w</span>/<span class="html-italic">v</span>; (<b>C</b>) 18% <span class="html-italic">w</span>/<span class="html-italic">v</span>; and (<b>D</b>) 20% <span class="html-italic">w</span>/<span class="html-italic">v</span>.</p>
Full article ">Figure 2
<p>Trend of the PCL mats average fiber diameter as function of the PCL solution concentrations.</p>
Full article ">Figure 3
<p>Influence of the applied voltage to the PCL solution of 20% <span class="html-italic">w</span>/<span class="html-italic">v</span> on electrospun fiber characteristics: (<b>A</b>) 10 kV; (<b>B</b>) 15 kV; and (<b>C</b>) 20 kV (scale bar 2 μm).</p>
Full article ">Figure 4
<p>Representative SEM micrographs of PCL nanofibers (scale bar 2 μm): (<b>A</b>) PCL 15% <span class="html-italic">w</span>/<span class="html-italic">v</span> in acetic acid; and (<b>B</b>) PCL 15% <span class="html-italic">w</span>/<span class="html-italic">v</span> in a mixture of acetic acid and formic acid (ratio 1:1).</p>
Full article ">Figure 5
<p>Light microscope image of PCL microfibers pattern (<b>A</b>). SEM micrographs of PCL microfibers pattern exhibiting large porosity at different magnifications: 100× (scale bar 100 μm) (<b>B</b>); and 200× (scale bar 100 μm) (<b>C</b>).</p>
Full article ">Figure 6
<p>Light Microscope image of PCL nanofibers pattern: with the narrow pattern (magnification 4×) (<b>A</b>); and with the wide pattern (magnification 1× and in the inlet 4×, scale bar 1 mm) (<b>B</b>).</p>
Full article ">Figure 7
<p>SEM micrographs of PCL and PCL-bioactive glass (BG) composite electrospun mats before immersion in simulated body fluid (SBF) solution (PCL d0 and PCL-BG d0 (<b>A</b>–<b>C</b>)) in the first row; after one day of immersion in SBF (PCL d1 and PCL-BG d1 (<b>D</b>–<b>F</b>)) in the second row; after four days of immersion in SBF (PCL d4 and PCL-BG d4 (<b>G</b>–<b>I</b>)); and after seven days of immersion in SBF (PCL d7 and PCL-BG d7 (<b>L</b>–<b>N</b>)).</p>
Full article ">Figure 8
<p>Energy dispersive X-ray (EDX) analysis of PCL-BG composite electrospun mats before immersion in SBF solution (PCL-BG d0) in the first row; after one day of immersion in SBF (PCL-BG d1) in the second row; after four days of immersion in SBF (PCL-BG d4); and after seven days of immersion in SBF (PCL-BG d7).</p>
Full article ">Figure 8 Cont.
<p>Energy dispersive X-ray (EDX) analysis of PCL-BG composite electrospun mats before immersion in SBF solution (PCL-BG d0) in the first row; after one day of immersion in SBF (PCL-BG d1) in the second row; after four days of immersion in SBF (PCL-BG d4); and after seven days of immersion in SBF (PCL-BG d7).</p>
Full article ">Figure 9
<p>Fourier transform infrared spectroscopy (FTIR) spectra in the range 3000–500 cm<sup>−1</sup> for electrospun samples of neat PCL (PCL), PCL with BG particles before immersion in SBF solution (PCL-BG d0) and after one day (PCL-BG d1) and four days (PCL-BG d4) of immersion in SBF solution (the characteristic peaks are discussed in the text).</p>
Full article ">Figure 10
<p>FTIR spectra in the range 1300–500 cm<sup>−1</sup> for electrospun samples of neat PCL (PCL), PCL with BG particles before immersion in SBF solution (PCL-BG d0) and after one day (PCL-BG d1) and four days (PCL-BG d4) of immersion in SBF solution (the characteristic peaks are discussed in the text).</p>
Full article ">Figure 11
<p>Digital images of electrospun fiber mats without (PCL20) and with BG particles (PCL-BG) before the mechanical testing.</p>
Full article ">
3987 KiB  
Article
Size- and Shape-Dependent Antibacterial Studies of Silver Nanoparticles Synthesized by Wet Chemical Routes
by Muhammad Akram Raza, Zakia Kanwal, Anum Rauf, Anjum Nasim Sabri, Saira Riaz and Shahzad Naseem
Nanomaterials 2016, 6(4), 74; https://doi.org/10.3390/nano6040074 - 15 Apr 2016
Cited by 586 | Viewed by 21845
Abstract
Silver nanoparticles (AgNPs) of different shapes and sizes were prepared by solution-based chemical reduction routes. Silver nitrate was used as a precursor, tri-sodium citrate (TSC) and sodium borohydride as reducing agents, while polyvinylpyrrolidone (PVP) was used as a stabilizing agent. The morphology, size, [...] Read more.
Silver nanoparticles (AgNPs) of different shapes and sizes were prepared by solution-based chemical reduction routes. Silver nitrate was used as a precursor, tri-sodium citrate (TSC) and sodium borohydride as reducing agents, while polyvinylpyrrolidone (PVP) was used as a stabilizing agent. The morphology, size, and structural properties of obtained nanoparticles were characterized by scanning electron microscopy (SEM), UV-visible spectroscopy (UV-VIS), and X-ray diffraction (XRD) techniques. Spherical AgNPs, as depicted by SEM, were found to have diameters in the range of 15 to 90 nm while lengths of the edges of the triangular particles were about 150 nm. The characteristic surface plasmon resonance (SPR) peaks of different spherical silver colloids occurring in the wavelength range of 397 to 504 nm, whereas triangular particles showed two peaks, first at 392 nm and second at 789 nm as measured by UV-VIS. The XRD spectra of the prepared samples indicated the face-centered cubic crystalline structure of metallic AgNPs. The in vitro antibacterial properties of all synthesized AgNPs against two types of Gram-negative bacteria, Pseudomonas aeruginosa and Escherichia coli were examined by Kirby–Bauer disk diffusion susceptibility method. It was noticed that the smallest-sized spherical AgNPs demonstrated a better antibacterial activity against both bacterial strains as compared to the triangular and larger spherical shaped AgNPs. Full article
(This article belongs to the Special Issue Recent Advances in Nanomaterials’ Research: Selection from ICSSP'15)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>The manifestation of different colors of silver nanoparticle samples, the type of sample is written on the lid of each sample bottle.</p>
Full article ">Figure 2
<p>Ultraviolet visible (UV-VIS) absorption spectra of all samples showing different surface plasmon resonance (SPR) peaks.</p>
Full article ">Figure 3
<p>SEM images of Sample 1 at lower (<b>a</b>) and higher (<b>b</b>) magnification showing the spherical morphology of the particles. The triangle-shaped silver particles are represented in (<b>c</b>) and (<b>d</b>) at different magnifications. The inset showed the color of sample S1 and sample S2 solution the beaker.</p>
Full article ">Figure 4
<p>SEM micrographs of sample S3 (<b>a</b>,<b>b</b>), S4 (<b>c</b>,<b>d</b>), and S5 (<b>e</b>,<b>f</b>) presenting the shape and size of preapred AgNPs. The inset showed the the color of correspoding colloidal sample.</p>
Full article ">Figure 5
<p>Xray difraction (XRD) pattern of sample 1 (S1), showing the face centered cubic (FCC) crystalline metallic silver nanoparticles (AgNPs). The intesity in vertical axis is mearred in counts per second (CPS) and diffraction angle (2 theta) measred is taken along horizental axis. The value of wavelngth (WL in angstrom) is also mentioned in the figure.</p>
Full article ">Figure 6
<p><span class="html-italic">Pseudomonas aeruginosa</span> zones of inhibition (ZOI) around silver nanoparticles (AgNPs) impregnated disks. The distance of the first colony from the disk/ZOI is demonstrated by arrow headed lines.</p>
Full article ">Figure 7
<p><span class="html-italic">Escherichia coli</span> zones of inhibition (ZOI) around silver nanoparticles (AgNPs) impregnated disks. The distance of the bacterial lawn from disk/ZOI is demonstrated by red lines.</p>
Full article ">Figure 8
<p>Antibacterial activity (high to low) of silver nanoparticles (AgNPs) against <span class="html-italic">Pseudomonas aeruginosa</span> and <span class="html-italic">Escherichia coli.</span></p>
Full article ">Figure 9
<p>Color changing of sample 1 at different phases of the reaction. (<b>a</b>) Transparent color appeared on dissolving silver nitrate into the water to form silver ions at boiling temperature under continuous stirring; (<b>b</b>) light yellow color indicated the reduction of silver ions into very small silver particles after the addition tri-sodium citrate; (<b>c</b>) bright yellow color depicted the formation of larger silver particles from the smaller ones; (<b>d</b>) finally greenish yellow color revealed the completion of the reaction when all silver ions had been reduced into the elemental silver nanoparticles by the tri-sodium citrate.</p>
Full article ">
0 pages, 1463 KiB  
Article
RETRACTED: Structural and Magnetic Response in Bimetallic Core/Shell Magnetic Nanoparticles
by Adeela Nairan, Usman Khan, Munawar Iqbal, Maaz Khan, Khalid Javed, Saira Riaz, Shahzad Naseem and Xiufeng Han
Nanomaterials 2016, 6(4), 72; https://doi.org/10.3390/nano6040072 - 14 Apr 2016
Cited by 11 | Viewed by 9045 | Retraction
Abstract
Bimagnetic monodisperse CoFe2O4/Fe3O4 core/shell nanoparticles have been prepared by solution evaporation route. To demonstrate preferential coating of iron oxide onto the surface of ferrite nanoparticles X-ray diffraction (XRD), High resolution transmission electron microscope (HR-TEM) and Raman [...] Read more.
Bimagnetic monodisperse CoFe2O4/Fe3O4 core/shell nanoparticles have been prepared by solution evaporation route. To demonstrate preferential coating of iron oxide onto the surface of ferrite nanoparticles X-ray diffraction (XRD), High resolution transmission electron microscope (HR-TEM) and Raman spectroscopy have been performed. XRD analysis using Rietveld refinement technique confirms single phase nanoparticles with average seed size of about 18 nm and thickness of shell is 3 nm, which corroborates with transmission electron microscopy (TEM) analysis. Low temperature magnetic hysteresis loops showed interesting behavior. We have observed large coercivity 15.8 kOe at T = 5 K, whereas maximum saturation magnetization (125 emu/g) is attained at T = 100 K for CoFe2O4/Fe3O4 core/shell nanoparticles. Saturation magnetization decreases due to structural distortions at the surface of shell below 100 K. Zero field cooled (ZFC) and Field cooled (FC) plots show that synthesized nanoparticles are ferromagnetic till room temperature and it has been noticed that core/shell sample possess high blocking temperature than Cobalt Ferrite. Results indicate that presence of iron oxide shell significantly increases magnetic parameters as compared to the simple cobalt ferrite. Full article
(This article belongs to the Special Issue Recent Advances in Nanomaterials’ Research: Selection from ICSSP'15)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>X-ray diffraction data and Rietveld profile fits of (<b>a</b>) core (CoFe<sub>2</sub>O<sub>4</sub>) and (<b>b</b>) core/shell (CoFe<sub>2</sub>O<sub>4</sub>/Fe<sub>3</sub>O<sub>4</sub>) ferrite nanoparticles.</p>
Full article ">Figure 2
<p>Room temperature Raman spectra of (<b>a</b>) core and (<b>b</b>) core/shell ferrite nanoparticles.</p>
Full article ">Figure 3
<p>(<b>a</b>) Transmission electron microscopy (TEM) image of core/shell nanoparticles; (<b>b</b>) high resolution (HR)-TEM image of core/shell nanoparticles.</p>
Full article ">Figure 4
<p>Temperature dependence of the field cooled (FC) and zero field cooled (ZFC) magnetizations for (<b>a</b>) core and (<b>b</b>) core/shell ferrite nanoparticles.</p>
Full article ">Figure 5
<p>Magnetization curves recoded at different temperatures ranging from 5 to 300 K for (<b>a</b>) core and (<b>b</b>) core/shell sample.</p>
Full article ">Figure 6
<p>Variation of the coercivity and saturation magnetization of (<b>a</b>) core nanoparticles with temperature and (<b>b</b>) core/shell nanoparticles with temperature.</p>
Full article ">
3198 KiB  
Article
Gold Nanoparticles: An Efficient Antimicrobial Agent against Enteric Bacterial Human Pathogen
by Shahzadi Shamaila, Noshin Zafar, Saira Riaz, Rehana Sharif, Jawad Nazir and Shahzad Naseem
Nanomaterials 2016, 6(4), 71; https://doi.org/10.3390/nano6040071 - 14 Apr 2016
Cited by 278 | Viewed by 11134
Abstract
Enteric bacterial human pathogens, i.e., Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Klebsiella pneumoniae, are the major cause of diarrheal infections in children and adults. Their structure badly affects the human immune system. It is important to explore new antibacterial agents instead [...] Read more.
Enteric bacterial human pathogens, i.e., Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Klebsiella pneumoniae, are the major cause of diarrheal infections in children and adults. Their structure badly affects the human immune system. It is important to explore new antibacterial agents instead of antibiotics for treatment. This project is an attempt to explain how gold nanoparticles affect these bacteria. We investigated the important role of the mean particle size, and the inhibition of a bacterium is dose-dependent. Ultra Violet (UV)-visible spectroscopy revealed the size of chemically synthesized gold nanoparticle as 6–40 nm. Atomic force microscopy (AFM) analysis confirmed the size and X-ray diffractometry (XRD) analysis determined the polycrystalline nature of gold nanoparticles. The present findings explained how gold nanoparticles lyse Gram-negative and Gram-positive bacteria. Full article
(This article belongs to the Special Issue Recent Advances in Nanomaterials’ Research: Selection from ICSSP'15)
Show Figures

Figure 1

Figure 1
<p>Ultra violet (UV)-visible spectrum of gold nanoparticles synthesized by the reduction of (<b>a</b>) 0.05 M NaBH<sub>4</sub> (G1), (<b>b</b>) 0.075 M NaBH<sub>4</sub> (G2) used as prepared.</p>
Full article ">Figure 2
<p>Atomic force microscopy (AFM) analysis of gold nanoparticles: (<b>a</b>,<b>b</b>) 2D image and histogram analysis of sample G1, respectively; (<b>c</b>,<b>d</b>) 2D image and histogram analysis of sample G2, respectively.</p>
Full article ">Figure 3
<p>X-ray diffraction pattern of chemically synthesized gold nanoparticles.</p>
Full article ">Figure 4
<p>(<b>a</b>) Percent growth of <span class="html-italic">S. aureus</span>, <span class="html-italic">B. subtilis</span>, <span class="html-italic">E. coli</span>, and <span class="html-italic">K. pneumonia</span> by G1 of gold NPs; (<b>b</b>) Percent growth of <span class="html-italic">S. aureus</span>, <span class="html-italic">B. subtilis</span>, <span class="html-italic">E. coli</span> and <span class="html-italic">K. pneumonia</span> by G2 of gold NPs.</p>
Full article ">Figure 5
<p>(<b>a</b>) Maximum inhibition concentration of sample G1 for <span class="html-italic">S. aureus</span>, <span class="html-italic">E. coli</span>, <span class="html-italic">B. subtilis</span> and <span class="html-italic">K. pneumonia</span>; (<b>b</b>) maximum inhibition concentration of sample G2 for <span class="html-italic">S. aureus</span> and <span class="html-italic">E. coli</span>, <span class="html-italic">B. subtilis</span> and <span class="html-italic">K. pneumonia</span> according to regression line.</p>
Full article ">Figure 6
<p>Well diffusion method of two sizes of gold nanoparticles (GNPs) against <span class="html-italic">E. coli</span> and <span class="html-italic">S. aureus.</span></p>
Full article ">
1658 KiB  
Communication
Highly-Efficient Plasmon-Enhanced Dye-Sensitized Solar Cells Created by Means of Dry Plasma Reduction
by Van-Duong Dao and Ho-Suk Choi
Nanomaterials 2016, 6(4), 70; https://doi.org/10.3390/nano6040070 - 14 Apr 2016
Cited by 32 | Viewed by 5485
Abstract
Plasmon-assisted energy conversion is investigated in a comparative study of dye-sensitized solar cells (DSCs) equipped with photo-anodes, which are fabricated by forming gold (Au) and silver (Ag) nanoparticles (NPs) on an fluorine-doped tin oxide (FTO) glass surface by means of dry plasma reduction [...] Read more.
Plasmon-assisted energy conversion is investigated in a comparative study of dye-sensitized solar cells (DSCs) equipped with photo-anodes, which are fabricated by forming gold (Au) and silver (Ag) nanoparticles (NPs) on an fluorine-doped tin oxide (FTO) glass surface by means of dry plasma reduction (DPR) and coating TiO2 paste onto the modified FTO glass through a screen printing method. As a result, the FTO/Ag-NPs/TiO2 photo-anode showed an enhancement of its photocurrent, whereas the FTO/Au-NPs/TiO2 photo-anode showed less photocurrent than even a standard photo-anode fabricated by simply coating TiO2 paste onto the modified FTO glass through screen printing. This result stems from the small size and high areal number density of Au-NPs on FTO glass, which prevent the incident light from reaching the TiO2 layer. Full article
(This article belongs to the Special Issue Plasma Nanoengineering and Nanofabrication)
Show Figures

Figure 1

Figure 1
<p>(<b>a</b>) High-Resolution Scanning Electron Microscopy (HRSEM) image of Ag-nanoparticles (NPs) on an fluorine-doped tin oxide (FTO) glass substrate; and (<b>b</b>) HRSEM image of Au-NPs on an FTO glass substrate.</p>
Full article ">Figure 2
<p>Current-voltage characteristics of three dye-sensitized solar cells (DSCs) equipped with different working electrodes.</p>
Full article ">Figure 3
<p>(<b>a</b>) Nyquist plots of three DSCs equipped with different working electrodes; and (<b>b</b>) The electrochemical impedance spectroscopy (EIS) Bode plots of three DSCs equipped with different working electrodes. Z’’: imaginary part of impedance; Z’: real part of impedance; CPE1: the constant phase element at counter electrode/electrolyte interface; CPE2: the constant phase element at working electrode/electrolyte interface; Rh: Ohmic internal resistance; Rct1: charge-transfer resistance at counter electrode/electrolyte interface; Rct2: charge-transfer resistance at working electrode/electrolyte interface; W1: Warburg impedance.</p>
Full article ">Figure 4
<p>(<b>a</b>) Absorption spectra of AuNPs and AgNPs; (<b>b</b>) Incident photon-to-current efficiency (IPCE) spectra of DSCs based on different working electrodes. a.u.: arbitrary unit.</p>
Full article ">
4652 KiB  
Article
Cationic Nanoparticles Assembled from Natural-Based Steroid Lipid for Improved Intracellular Transport of siRNA and pDNA
by Ruilong Sheng, Xiaoqing Zhuang, Zhao Wang, Amin Cao, Kaili Lin and Julian X. X. Zhu
Nanomaterials 2016, 6(4), 69; https://doi.org/10.3390/nano6040069 - 13 Apr 2016
Cited by 11 | Viewed by 6653
Abstract
Developing new functional biomaterials from biocompatible natural-based resources for gene/drug delivery has attracted increasing attention in recent years. In this work, we prepared a series of cationic nanoparticles (Diosarg-DOPE NPs) by assembly of a natural steroid diosgenin-based cationic lipid (Diosarg) with commercially-available helper [...] Read more.
Developing new functional biomaterials from biocompatible natural-based resources for gene/drug delivery has attracted increasing attention in recent years. In this work, we prepared a series of cationic nanoparticles (Diosarg-DOPE NPs) by assembly of a natural steroid diosgenin-based cationic lipid (Diosarg) with commercially-available helper lipid 1,2-dioleoyl-sn-glycero-3-phosphorethanolamine (DOPE). These cationic Diosarg-DOPE NPs were able to efficiently bind siRNA and plasmid DNA (pDNA) via electrostatic interactions to form stable, nano-sized cationic lipid nanoparticles instead of lamellar vesicles in aqueous solution. The average particle size, zeta potentials and morphologies of the siRNA and pDNA complexes of the Diosarg-DOPE NPs were examined. The in vitro cytotoxicity of NPs depends on the dose and assembly ratio of the Diosarg and DOPE. Notably, the intracellular transportation efficacy of the exogenesis siRNA and pDNA could be greatly improved by using the Diosarg-DOPE NPs as the cargoes in H1299 cell line. The results demonstrated that the self-assembled Diosarg-DOPE NPs could achieve much higher intracellular transport efficiency for siRNA or pDNA than the cationic lipid Diosarg, indicating that the synergetic effect of different functional lipid components may benefit the development of high efficiency nano-scaled gene carriers. Moreover, it could be noted that the traditional “lysosome localization” involved in the intracellular trafficking of the Diosarg and Diosarg-DOPE NPs, indicating the co-assembly of helper lipid DOPE, might not significantly affect the intracellular localization features of the cationic lipids. Full article
(This article belongs to the Special Issue DNA-Based Nanotechnology)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Transmission electron microscopy (TEM) photographs of the Diosarg-DOPE aggregates: (<b>a</b>) Diosarg-DOPE (2:1) nanoparticles (NPs); (<b>b</b>) Diosarg-DOPE (1:1) NPs; (<b>c</b>) Diosarg-DOPE (1:2) NPs; scale bar: 200 nm.</p>
Full article ">Figure 2
<p>Storage stability of the Diosarg-DOPE (2:1, 1:1, 1:2) NPs in distilled water after 0 day, 7 days and 14 days; the average particle size was measured by the dynamic light scattering instrument.</p>
Full article ">Figure 3
<p>Average particle sizes and zeta potentials of the Diosarg/siRNA and Diosarg-DOPE NPs/siRNA (<b>a</b>,<b>b</b>), as well as the Diosarg/pDNA (<b>c</b>) and Diosarg-DOPE NPs/pDNA (<b>d</b>) complexes under the +/− charge ratios from 0 to 30 determined by DLS.</p>
Full article ">Figure 4
<p>Cytotoxicity of H1299 cells incubated with the Diosarg lipid and Diosarg-DOPE NPs at various +/− charge ratios (pDNA 0.5 μg/well), with the Diosarg lipid at the same +/− charge ratio as the control.</p>
Full article ">Figure 5
<p>Intracellular uptake of the Diosarg lipid and Diosarg-DOPE (2:1, 1:1, 1:2) NPs/Cy3-siRNA complexes (+/− = 10) in H1299 cells measured by flow cytometry (10,000 cells for each sample) and observed by fluorescence microscopy (blue: DAPI (4’,6-diamidino-2-phenylindole) stained nuclei; red: Cy3-labeled siRNA).</p>
Full article ">Figure 6
<p>Intracellular uptake of the Diosarg lipid and Diosarg-DOPE (2:1, 1:1, 1:2)/Cy3-pDNA complexes (+/− = 10) in H1299 cells measured by flow cytometry (10,000 cells for each sample) and observed by fluorescence microscopy (blue: DAPI stained nuclei; red: Cy3-labeled pDNA).</p>
Full article ">Figure 7
<p><span class="html-italic">In vitro</span> luciferase gene transfection efficiencies of the Diosarg lipid and Diosarg-DOPE (2:1, 1:1, 1:2) NPs/pDNA complexes at various +/− charge ratios in H1299 cells.</p>
Full article ">Figure 8
<p>Intracellular localization of the Diosarg lipid and Diosarg-DOPE (1:1)/pDNA complexes (+/− = 10) in H1299 cells observed and recorded by fluorescence microscopy (blue: DAPI stained cell nuclei; green: Lysotracker-stained lysosome; red: Cy3-labeled pDNA).</p>
Full article ">Scheme 1
<p>Preparation of Diosarg-1,2-dioleoyl-<math display="inline"> <semantics> <mrow> <mstyle mathcolor="red"> <mi>sn</mi> </mstyle> </mrow> </semantics> </math>-glycero-3-phosphor-ethanolamine (DOPE) nanoparticles as gene (siRNA and DNA) carriers for intracellular gene transportation.</p>
Full article ">
1390 KiB  
Communication
Gold Nanomaterial Uptake from Soil Is Not Increased by Arbuscular Mycorrhizal Colonization of Solanum Lycopersicum (Tomato)
by Jonathan D. Judy, Jason K. Kirby, Mike J. McLaughlin, Timothy Cavagnaro and Paul M. Bertsch
Nanomaterials 2016, 6(4), 68; https://doi.org/10.3390/nano6040068 - 13 Apr 2016
Cited by 10 | Viewed by 4880
Abstract
Bioaccumulation of engineered nanomaterials (ENMs) by plants has been demonstrated in numerous studies over the past 5–10 years. However, the overwhelming majority of these studies were conducted using hydroponic systems and the degree to which the addition of the biological and chemical components [...] Read more.
Bioaccumulation of engineered nanomaterials (ENMs) by plants has been demonstrated in numerous studies over the past 5–10 years. However, the overwhelming majority of these studies were conducted using hydroponic systems and the degree to which the addition of the biological and chemical components present in the soil might fundamentally alter the potential of plant bioaccumulation of ENMs is unclear. Here, we used two genotypes of Solanum lycopersicum (tomato), reduced mycorrhizal colonization (rmc), a mutant which does not allow arbuscular mycorrhizal fungi (AMF) colonization, and its progenitor, 76R, to examine how colonization by AMF alters trends of gold ENM bioaccumulation from a natural soil. Gold was taken up and bioaccumulated by plants of both genotypes. Gold concentrations were significantly higher in the rmc treatment although this was likely attributable to the large differences in biomass between the 76R and rmc plants. Regardless, there was little evidence that AMF played a significant role in trafficking Au ENMs into the plants. Furthermore, despite very low NH4NO3 extractable Au concentrations, Au accumulated at the root-soil interface. Although this observation would seem to suggest that ENMs may have potential to influence this particularly biologically active and important soil compartment, we observed no evidence of this here, as the 76R plants developed a robust AMF symbiosis despite accumulation of Au ENMs at the rhizoplane. Full article
(This article belongs to the Special Issue Engineered Nanomaterials in the Environment)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Dry shoot biomass (<b>A</b>); mycorrhizal colonization frequency (<b>B</b>); shoot Au concentrations (<b>C</b>); and shoot Au uptake (<b>D</b>) measured in 76R and <span class="html-italic">rmc</span> tomato plants. Error bars represent standard deviation. The * indicates a significant difference at α ≤ 0.01 as determined by a either a 2-sided <span class="html-italic">T</span>-test (concentration and uptake) or a Mann-Whitney <span class="html-italic">U</span>-test (biomass and colonization).</p>
Full article ">Figure 2
<p>Micrographs (<b>left</b>) and laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) maps (<b>right</b>) of root cross-sections collected from root samples from (<b>top</b>) 76R and (<b>bottom</b>) <span class="html-italic">rmc</span> tomato plants. Color bars inset in LA-ICP-MS maps show relationship between counts per second (CPS) and color for each map. Ep = epidermis. En = endodermis. Lr = lateral root.</p>
Full article ">Figure 3
<p>TEM (transmission electron microscopy) micrograph and energy-dispersive X-ray spectroscopy (EDS) spectrum characterizing gold engineered nanomaterials (ENMs). Copper detected is result of the use of Cu TEM grids. cps: counts per second.</p>
Full article ">
2575 KiB  
Article
PMN-PT/PVDF Nanocomposite for High Output Nanogenerator Applications
by Chuan Li, Wenbo Luo, Xingzhao Liu, Dong Xu and Kai He
Nanomaterials 2016, 6(4), 67; https://doi.org/10.3390/nano6040067 - 11 Apr 2016
Cited by 39 | Viewed by 6616
Abstract
The 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3(0.7PMN-0.3PT) nanorods were obtained via hydrothermal method with high yield (over 78%). Then, new piezoelectric nanocomposites based on (1−x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) nanorods were fabricated [...] Read more.
The 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3(0.7PMN-0.3PT) nanorods were obtained via hydrothermal method with high yield (over 78%). Then, new piezoelectric nanocomposites based on (1−x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) nanorods were fabricated by dispersing the 0.7PMN-0.3PT nanorods into piezoelectric poly(vinylidene fluoride) (PVDF) polymer. The mechanical behaviors of the nanocomposites were investigated. The voltage and current generation of PMN-PT/PVDF nanocomposites were also measured. The results showed that the tensile strength, yield strength, and Young’s modulus of nanocomposites were enhanced as compared to that of the pure PVDF. The largest Young’s modulus of 1.71 GPa was found in the samples with 20 wt % nanorod content. The maximum output voltage of 10.3 V and output current of 46 nA were obtained in the samples with 20 wt % nanorod content, which was able to provide a 13-fold larger output voltage and a 4.5-fold larger output current than that of pure PVDF piezoelectric polymer. The current density of PMN-PT/PVDF nanocomposites is 20 nA/cm2. The PMN-PT/PVDF nanocomposites exhibited great potential for flexible self-powered sensing applications. Full article
(This article belongs to the Special Issue Multifunctional Polymer-Based Nanocomposites)
Show Figures

Figure 1

Figure 1
<p>(<b>a</b>) X-ray powder diffraction (XRD) pattern of the (1−<span class="html-italic">x</span>)Pb(Mg<sub>1/3</sub>Nb<sub>2/3</sub>)O<sub>3</sub>-<span class="html-italic">x</span>PbTiO<sub>3</sub> (PMN-PT) nanorods; (<b>b</b>) scanning electron microscope (SEM) images of PMN-PT nanorods, and the inset indicates the corresponding higher magnification SEM image.</p>
Full article ">Figure 2
<p>Surface morphology of nanocomposite films with (<b>a</b>) 0 wt %; (<b>b</b>) 10 wt %; (<b>c</b>) 20 wt % and (<b>d</b>) 25 wt % PMN-PT nanorod content.</p>
Full article ">Figure 3
<p>Stress–strain curves of nanocomposites with different PMN-PT content.</p>
Full article ">Figure 4
<p>Voltage generation under a periodic mechanical tapping. (<b>a</b>) Pure PVDF; (<b>b</b>) 10 wt % PMN-PT; (<b>c</b>) 20 wt % PMN-PT; and (<b>d</b>) 25 wt % PMN-PT.</p>
Full article ">Figure 5
<p>Current generation under a periodic mechanical tapping. (<b>a</b>) Pure PVDF; (<b>b</b>) 10 wt % PMN-PT; (<b>c</b>) 20 wt % PMN-PT; and (<b>d</b>) 25% PMN-PT.</p>
Full article ">
2443 KiB  
Article
Automatic Echographic Detection of Halloysite Clay Nanotubes in a Low Concentration Range
by Francesco Conversano, Paola Pisani, Ernesto Casciaro, Marco Di Paola, Stefano Leporatti, Roberto Franchini, Alessandra Quarta, Giuseppe Gigli and Sergio Casciaro
Nanomaterials 2016, 6(4), 66; https://doi.org/10.3390/nano6040066 - 11 Apr 2016
Cited by 5 | Viewed by 5074
Abstract
Aim of this work was to investigate the automatic echographic detection of an experimental drug delivery agent, halloysite clay nanotubes (HNTs), by employing an innovative method based on advanced spectral analysis of the corresponding “raw” radiofrequency backscatter signals. Different HNT concentrations in a [...] Read more.
Aim of this work was to investigate the automatic echographic detection of an experimental drug delivery agent, halloysite clay nanotubes (HNTs), by employing an innovative method based on advanced spectral analysis of the corresponding “raw” radiofrequency backscatter signals. Different HNT concentrations in a low range (5.5–66 × 1010 part/mL, equivalent to 0.25–3.00 mg/mL) were dispersed in custom-designed tissue-mimicking phantoms and imaged through a clinically-available echographic device at a conventional ultrasound diagnostic frequency (10 MHz). The most effective response (sensitivity = 60%, specificity = 95%), was found at a concentration of 33 × 1010 part/mL (1.5 mg/mL), representing a kind of best compromise between the need of enough particles to introduce detectable spectral modifications in the backscattered signal and the necessity to avoid the losses of spectral peculiarity associated to higher HNT concentrations. Based on theoretical considerations and quantitative comparisons with literature-available results, this concentration could also represent an optimal concentration level for the automatic echographic detection of different solid nanoparticles when employing a similar ultrasound frequency. Future dedicated studies will assess the actual clinical usefulness of the proposed approach and the potential of HNTs for effective theranostic applications. Full article
(This article belongs to the Special Issue Nanoparticles in Bioimaging)
Show Figures

Figure 1

Figure 1
<p>Typical transmission electron microscopy (TEM) images of halloysite clay nanotubes (HNTs): (<b>a</b>) panoramic image, showing the grade of polydispersity of HNT length (scale bar: 500 nm); and (<b>b</b>) high-magnification image, showing the hollow tubular structure of HNTs (scale bar: 100 nm).</p>
Full article ">Figure 2
<p>Fourier transform infrared (FT-IR) spectrum of HNTs: the arrow indicates the peak due to the Si–H signal (2120 cm<sup>−1</sup>).</p>
Full article ">Figure 3
<p>Scanning force microscopy (SFM) “tapping amplitude” image of a single HNT and corresponding section analysis (inset). (image size: 2.5 μm).</p>
Full article ">Figure 4
<p>Automatic detection experiments: (<b>a</b>) scheme of the adopted phantom; (<b>b</b>) B-mode image of a control phantom (HNT concentration = 0 part/mL) with indication of the chosen region of interest (ROI); (<b>c</b>–<b>e</b>) sample images of the analyzed ROIs with the superimposed color maps for automatic HNT detection at the following concentrations: 16.5 × 10<sup>10</sup> part/mL (<b>c</b>); 33 × 10<sup>10</sup> part/mL (<b>d</b>); 66 × 10<sup>10</sup> part/mL (<b>e</b>).</p>
Full article ">Figure 5
<p>Diagnostic performance of the automatic HNT detection algorithm expressed through the plot of sensitivity and specificity as a function of HNT concentration. Error bars represent standard deviations, where visible.</p>
Full article ">Figure 6
<p>Scheme of the experimental data acquisition setup.</p>
Full article ">
1756 KiB  
Article
Facile Synthesis of Gd-Functionalized Gold Nanoclusters as Potential MRI/CT Contrast Agents
by Wenjun Le, Shaobin Cui, Xin Chen, Huanhuan Zhu, Bingdi Chen and Zheng Cui
Nanomaterials 2016, 6(4), 65; https://doi.org/10.3390/nano6040065 - 9 Apr 2016
Cited by 30 | Viewed by 6828
Abstract
Multi-modal imaging plays a key role in the earlier detection of disease. In this work, a facile bioinspired method was developed to synthesize Gd-functionalized gold nanoclusters (Gd-Au NCs). The Gd-Au NCs exhibit a uniform size, with an average size of 5.6 nm in [...] Read more.
Multi-modal imaging plays a key role in the earlier detection of disease. In this work, a facile bioinspired method was developed to synthesize Gd-functionalized gold nanoclusters (Gd-Au NCs). The Gd-Au NCs exhibit a uniform size, with an average size of 5.6 nm in dynamic light scattering (DLS), which is a bit bigger than gold clusters (3.74 nm, DLS), while the fluorescent properties of Gd-Au NCs are almost the same as that of Au NCs. Moreover, the Gd-Au NCs exhibit a high longitudinal relaxivity value (r1) of 22.111 s−1 per mM of Gd in phosphate-buffered saline (PBS), which is six times higher than that of commercial Magnevist (A complex of gadolinium with a chelating agent, diethylenetriamine penta-acetic acid, Gd-DTPA, r1 = 3.56 mM−1·s−1). Besides, as evaluated by nano single photon emission computed tomography (SPECT) and computed tomography (CT) the Gd-Au NCs have a potential application as CT contrast agents because of the Au element. Finally, the Gd-Au NCs show little cytotoxicity, even when the Au concentration is up to 250 μM. Thus, the Gd-Au NCs can act as multi-modal imaging contrast agents. Full article
(This article belongs to the Special Issue Nanoparticles in Bioimaging)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>(<b>a</b>) Transmission electron microscopy image of as-prepared Gd-Au nanoclusters; (<b>b</b>) The result of dynamic light scattering.</p>
Full article ">Figure 2
<p>(<b>a</b>) Ultraviolet–visible absorption spectra of Au nanoclusters (NCs) (black curve) and Gd-Au NCs (red curve), Abs (Absorbance), a.u. (Absorbance Unit); (<b>b</b>) The corresponding fluorescent emission spectra of Au NCs (black curve) and Gd-Au NCs (red curve); (<b>c</b>) Bright photograph of Au NCs (left) and Gd-Au NCs (right); (<b>d</b>) The corresponding fluorescent photograph of Au NCs (left) and Gd-Au NCs (right) was taken under a porTable 365 nm UV-lamp (Min hang, Shanghai, China).</p>
Full article ">Figure 3
<p>(<b>a</b>) Longitudinal (T1) and transverse (T2) relaxation times of Gd-Au NCs (the slopes response to the longitudinal relaxivity value r1( blue) and transverse relaxivity value r2 (black)); (<b>b</b>) Magnetic resonance images of the Gd-Au NCs with Gd concentrations ranging from 0.08 to 0.40 mM and H<sub>2</sub>O; (<b>c</b>) Computed tomography of the Gd-Au NCs containing various Au concentrations and H<sub>2</sub>O.</p>
Full article ">Figure 4
<p><span class="html-italic">In vitro</span> cytotoxicity of Au NCs (black) and Gd-Au NCs (red) against breast cancer cell line (MCF-7) after 24 h.</p>
Full article ">
2523 KiB  
Communication
Morphology-Controlled High-Efficiency Small Molecule Organic Solar Cells without Additive Solvent Treatment
by Il Ku Kim, Jun Hyung Jo and Jung-Ho Yun
Nanomaterials 2016, 6(4), 64; https://doi.org/10.3390/nano6040064 - 8 Apr 2016
Cited by 11 | Viewed by 7060
Abstract
This paper focuses on nano-morphology-controlled small-molecule organic solar cells without solvent treatment for high power-conversion efficiencies (PCEs). The maximum high PCE reaches up to 7.22% with a bulk-heterojunction (BHJ) thickness of 320 nm. This high efficiency was obtained by eliminating solvent additives such [...] Read more.
This paper focuses on nano-morphology-controlled small-molecule organic solar cells without solvent treatment for high power-conversion efficiencies (PCEs). The maximum high PCE reaches up to 7.22% with a bulk-heterojunction (BHJ) thickness of 320 nm. This high efficiency was obtained by eliminating solvent additives such as 1,8-diiodooctane (DIO) to find an alternative way to control the domain sizes in the BHJ layer. Furthermore, the generalized transfer matrix method (GTMM) analysis has been applied to confirm the effects of applying a different thickness of BHJs for organic solar cells from 100 to 320 nm, respectively. Finally, the study showed an alternative way to achieve high PCE organic solar cells without additive solvent treatments to control the morphology of the bulk-heterojunction. Full article
(This article belongs to the Special Issue Nanostructured Solar Cells)
Show Figures

Figure 1

Figure 1
<p>(<b>a</b>) Chemical structures of <span class="html-italic">p</span>-DTS(FBTTh<sub>2</sub>)<sub>2</sub> and PC<sub>70</sub>BM; (<b>b</b>) device architecture for small-molecule bulk-heterojunction organic solar cells (SM BHJ OSCs); (<b>c</b>) band diagram of SM BHJ OSCs.</p>
Full article ">Figure 2
<p>Measured density/voltage (<span class="html-italic">J</span>-<span class="html-italic">V</span>) curves of SM BHJ OSCs.</p>
Full article ">Figure 3
<p>Measured external quantum efficiency (EQE) spectra of SM BHJ OSCs.</p>
Full article ">Figure 4
<p>Simulation results of charge generation rates of SM BHJ OSCs: (<b>a</b>) BHJ active layer = 100 nm; (<b>b</b>) BHJ active layer = 200 nm; (<b>c</b>) BHJ active layer = 320 nm.</p>
Full article ">Figure 5
<p>Measured atomic force microscopy (AFM) image of BHJ with a thickness of 320 nm: (<b>a</b>) top view of AFM; (<b>b</b>) measured cross-section of BHJ.</p>
Full article ">
146 KiB  
Editorial
Nanostructured Materials for Li-Ion Batteries and Beyond
by Xifei Li and Xueliang Sun
Nanomaterials 2016, 6(4), 63; https://doi.org/10.3390/nano6040063 - 7 Apr 2016
Cited by 7 | Viewed by 4438
Abstract
This Special Issue “Nanostructured Materials for Li-Ion Batteries and Beyond” of Nanomaterials is focused on advancements in the synthesis, optimization, and characterization of nanostructured materials, with an emphasis on the application of nanomaterials for building high performance Li-ion batteries (LIBs) and future systems.[...] [...] Read more.
This Special Issue “Nanostructured Materials for Li-Ion Batteries and Beyond” of Nanomaterials is focused on advancements in the synthesis, optimization, and characterization of nanostructured materials, with an emphasis on the application of nanomaterials for building high performance Li-ion batteries (LIBs) and future systems.[...] Full article
(This article belongs to the Special Issue Nanostructured Materials for Li-Ion Batteries and Beyond)
495 KiB  
Erratum
Erratum: Tsai, S.-L.; et al. The Coupled Photothermal Reaction and Transport in a Laser Additive Metal Nanolayer Simultaneous Synthesis and Pattering for Flexible Electronics. Nanomaterials 2016, 6, 12
by Nanoterials Editorial Office
Nanomaterials 2016, 6(4), 62; https://doi.org/10.3390/nano6040062 - 7 Apr 2016
Viewed by 3519
Abstract
Due to an error during production, the Figure 7b in the published paper [1] was incorrect. The correct figure is as follows:[...] Full article
Show Figures

Figure 7

Figure 7
<p>(<b>a</b>) Thickness of the silver film (<b>b</b>) reflectivity for 532 nm wavelength light <span class="html-italic">versus</span> number of laser scans (symbols: experimental data, lines: fitted curves).</p>
Full article ">
1416 KiB  
Article
Synergistic Antibacterial Effects of Nanoparticles Encapsulated with Scutellaria baicalensis and Pure Chlorhexidine on Oral Bacterial Biofilms
by Ken Cham-Fai Leung, Chaminda Jayampath Seneviratne, Xuan Li, Ping Chung Leung, Clara Bik San Lau, Chi-Hin Wong, Ka Yan Pang, Chun Wai Wong, Elaine Wat and Lijian Jin
Nanomaterials 2016, 6(4), 61; https://doi.org/10.3390/nano6040061 - 7 Apr 2016
Cited by 43 | Viewed by 7226
Abstract
Scutellaria baicalensis (SB) is a traditional Chinese medicine for treating infectious and inflammatory diseases. Our recent study shows potent antibacterial effects of nanoparticle-encapsulated chlorhexidine (Nano-CHX). Herein, we explored the synergistic effects of the nanoparticle-encapsulated SB (Nano-SB) and Nano-CHX on oral bacterial biofilms. Loading [...] Read more.
Scutellaria baicalensis (SB) is a traditional Chinese medicine for treating infectious and inflammatory diseases. Our recent study shows potent antibacterial effects of nanoparticle-encapsulated chlorhexidine (Nano-CHX). Herein, we explored the synergistic effects of the nanoparticle-encapsulated SB (Nano-SB) and Nano-CHX on oral bacterial biofilms. Loading efficiency of Nano-SB was determined by thermogravimetric analysis, and its releasing profile was assessed by high-performance liquid chromatographyusing baicalin (a flavonoid compound of SB) as the marker. The mucosal diffusion assay on Nano-SB was undertaken in a porcine model. The antibacterial effects of the mixed nanoparticles (Nano-MIX) of Nano-SB and Nano-CHX at 9:1 (w/w) ratio were analyzed in both planktonic and biofilm modes of representative oral bacteria. The Nano-MIX was effective on the mono-species biofilms of Streptococcus (S.) mutans, S. sobrinus, Fusobacterium (F.) nucleatum, and Aggregatibacter (A.) actinomycetemcomitans (MIC 50 μg/mL) at 24 h, and exhibited an enhanced effect against the multi-species biofilms such as S. mutans, F. nucleatum, A. actinomycetemcomitans, and Porphyromonas (P.) gingivalis (MIC 12.5 μg/mL) at 24 h that was supported by the findings of both scanning electron microscopy (SEM) and confocal scanning laser microscopy (CLSM). This study shows enhanced synergistic antibacterial effects of the Nano-MIX on common oral bacterial biofilms, which could be potentially developed as a novel antimicrobial agent for clinical oral/periodontal care. Full article
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>The thermogravimetric analysis on the weight losses of nanoparticle-encapsulated <span class="html-italic">Scutellaria</span> <span class="html-italic">baicalensis</span> (Nano-SB) (5.2%) (<b>upper</b>) and blank nanoparticles (3.2%) (<b>lower</b>) between 100 °C and 900 °C.</p>
Full article ">Figure 2
<p>The high-performance liquid chromatography (HPLC) profiles of (<b>A</b>) baicalin; (<b>B</b>) SB aqueous extract; and (<b>C</b>) Nano-SB. Detection was performed at 274 nm, and the retention time of baicalin was assigned at 12.5 min.</p>
Full article ">Figure 3
<p>Effect of the Nano-MIX on the multi-species biofilms of <span class="html-italic">S. mutans</span>, <span class="html-italic">F. nucleatum</span>, <span class="html-italic">A. actinomycetemcomitans</span>, and <span class="html-italic">P. gingivalis</span> at 24 h. The confocal scanning laser microscopy (CLSM) (<b>A</b>,<b>B</b>) and scanning electron microscopy (SEM) images (<b>C</b>,<b>D</b>) showing comparative antibacterial effects of the Nano-MIX treatment (<b>B</b>,<b>D</b>) on the mixed-species oral biofilms with reference to the blank nanoparticles (<b>A</b>,<b>C</b>), respectively.</p>
Full article ">
3379 KiB  
Article
Synthesis of Lithium Metal Oxide Nanoparticles by Induction Thermal Plasmas
by Manabu Tanaka, Takuya Kageyama, Hirotaka Sone, Shuhei Yoshida, Daisuke Okamoto and Takayuki Watanabe
Nanomaterials 2016, 6(4), 60; https://doi.org/10.3390/nano6040060 - 6 Apr 2016
Cited by 31 | Viewed by 9810
Abstract
Lithium metal oxide nanoparticles were synthesized by induction thermal plasma. Four different systems—Li–Mn, Li–Cr, Li–Co, and Li–Ni—were compared to understand formation mechanism of Li–Me oxide nanoparticles in thermal plasma process. Analyses of X-ray diffractometry and electron microscopy showed that Li–Me oxide nanoparticles were [...] Read more.
Lithium metal oxide nanoparticles were synthesized by induction thermal plasma. Four different systems—Li–Mn, Li–Cr, Li–Co, and Li–Ni—were compared to understand formation mechanism of Li–Me oxide nanoparticles in thermal plasma process. Analyses of X-ray diffractometry and electron microscopy showed that Li–Me oxide nanoparticles were successfully synthesized in Li–Mn, Li–Cr, and Li–Co systems. Spinel structured LiMn2O4 with truncated octahedral shape was formed. Layer structured LiCrO2 or LiCoO2 nanoparticles with polyhedral shapes were also synthesized in Li–Cr or Li–Co systems. By contrast, Li–Ni oxide nanoparticles were not synthesized in the Li–Ni system. Nucleation temperatures of each metal in the considered system were evaluated. The relationship between the nucleation temperature and melting and boiling points suggests that the melting points of metal oxides have a strong influence on the formation of lithium metal oxide nanoparticles. A lower melting temperature leads to a longer reaction time, resulting in a higher fraction of the lithium metal oxide nanoparticles in the prepared nanoparticles. Full article
(This article belongs to the Special Issue Plasma Nanoengineering and Nanofabrication)
Show Figures

Figure 1

Figure 1
<p>X-ray diffractometry (XRD) spectra of as-prepared nanoparticles by induction thermal plasma in different systems, Li–Mn, Li–Co, Li–Cr, and Li–Ni.</p>
Full article ">Figure 2
<p>Composition of prepared nanoparticles by induction thermal plasma in different systems, Li–Mn, Li–Co, Li–Cr, and Li–Ni.</p>
Full article ">Figure 3
<p>(<b>a</b>) Representative transmission electron microscopy (TEM) image and particle size distribution of prepared nanoparticles by induction thermal plasma in Li–Mn system; (<b>b</b>) that in Li–Cr system; (<b>c</b>) that in Li–Co system; (<b>d</b>) that in Li–Ni system.</p>
Full article ">Figure 4
<p>Representative scanning electron microscopy (SEM) image of prepared nanoparticles in Li–Mn system.</p>
Full article ">Figure 5
<p>Relationship between nucleation temperature and melting and boiling points of considered metals and metal oxides.</p>
Full article ">Figure 6
<p>Relationship between lowest melting points of metal oxides and the reaction ratios for each Li–Me system.</p>
Full article ">Figure 7
<p>Conceptual diagram of formation mechanism of Li–Me oxide nanoparticles in induction thermal plasma.</p>
Full article ">Figure 8
<p>Schematic illustration of induction thermal plasma system for nanoparticles fabrication (<b>a</b>) and enlarged illustration of plasma torch (<b>b</b>).</p>
Full article ">
11370 KiB  
Article
Nickel Decorated on Phosphorous-Doped Carbon Nitride as an Efficient Photocatalyst for Reduction of Nitrobenzenes
by Anurag Kumar, Pawan Kumar, Chetan Joshi, Manvi Manchanda, Rabah Boukherroub and Suman L. Jain
Nanomaterials 2016, 6(4), 59; https://doi.org/10.3390/nano6040059 - 1 Apr 2016
Cited by 133 | Viewed by 11692
Abstract
Nickel nanoparticle-decorated phosphorous-doped graphitic carbon nitride (Ni@g-PC3N4) was synthesized and used as an efficient photoactive catalyst for the reduction of various nitrobenzenes under visible light irradiation. Hydrazine monohydrate was used as the source of protons and electrons for the [...] Read more.
Nickel nanoparticle-decorated phosphorous-doped graphitic carbon nitride (Ni@g-PC3N4) was synthesized and used as an efficient photoactive catalyst for the reduction of various nitrobenzenes under visible light irradiation. Hydrazine monohydrate was used as the source of protons and electrons for the intended reaction. The developed photocatalyst was found to be highly active and afforded excellent product yields under mild experimental conditions. In addition, the photocatalyst could easily be recovered and reused for several runs without any detectable leaching during the reaction. Full article
(This article belongs to the Special Issue Nanoparticles for Catalysis)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Field emission scanning electron microscopy (FE-SEM) image of: (<b>a</b>) graphitic carbon nitride (g-C<sub>3</sub>N<sub>4</sub>); (<b>b</b>) phosphorous-doped graphitic carbon nitride (g-PC<sub>3</sub>N<sub>4</sub>); (<b>c</b>) nickel nanoparticle-grafted g-PC<sub>3</sub>N<sub>4</sub> (Ni@g-PC<sub>3</sub>N<sub>4</sub>); energy dispersive X-ray spectroscopy (EDX) pattern of: (<b>d</b>) g-C<sub>3</sub>N<sub>4</sub>; (<b>e</b>) g-PC<sub>3</sub>N<sub>4</sub>; (<b>f</b>) 5%Ni@g-PC<sub>3</sub>N<sub>4</sub>.</p>
Full article ">Figure 2
<p>Transmission electron microscopy (TEM) images of: (<b>a</b>) g-C<sub>3</sub>N<sub>4</sub>; (<b>b</b>) g-PC<sub>3</sub>N<sub>4</sub>; (<b>c</b>) Ni@g-PC<sub>3</sub>N<sub>4</sub>; (<b>d</b>) selected area electron diffraction (SAED) pattern of Ni@g-PC<sub>3</sub>N<sub>4</sub>; (<b>e</b>) EDX pattern of Ni@g-PC<sub>3</sub>N<sub>4</sub>.</p>
Full article ">Figure 3
<p>Fourier transform infrared (FTIR) spectra of: (<b>a</b>) nickel nanoparticles (NiNPs); (<b>b</b>) g-C<sub>3</sub>N<sub>4</sub>; (<b>c</b>) g-PC<sub>3</sub>N<sub>4</sub>; (<b>d</b>) 5%Ni@g-PC<sub>3</sub>N<sub>4</sub>.</p>
Full article ">Figure 4
<p>X-ray diffraction (XRD) patterns of: (<b>a</b>) g-C<sub>3</sub>N<sub>4</sub>; (<b>b</b>) g-PC<sub>3</sub>N<sub>4</sub>; (<b>c</b>) 5%Ni@g-PC<sub>3</sub>N<sub>4</sub>. a.u.: arbitrary units.</p>
Full article ">Figure 5
<p>N<sub>2</sub> adsorption-desorption isotherm and pore size distribution of: (<b>a</b>) g-C<sub>3</sub>N<sub>4</sub>; (<b>b</b>) g-PC<sub>3</sub>N<sub>4</sub>; (<b>c</b>) 5%Ni@g-PC<sub>3</sub>N<sub>4</sub>.</p>
Full article ">Figure 6
<p>Ultraviolet--visible (UV-Vis) absorption spectra of: (<b>a</b>) g-C<sub>3</sub>N<sub>4</sub>; (<b>b</b>) g-PC<sub>3</sub>N<sub>4</sub>; (<b>c</b>) 5%Ni@g-PC<sub>3</sub>N<sub>4</sub>.</p>
Full article ">Figure 7
<p>Tauc plots of (<b>a</b>) g-C<sub>3</sub>N<sub>4</sub>; (<b>b</b>) g-PC<sub>3</sub>N<sub>4</sub>; (<b>c</b>) Ni@g-PC<sub>3</sub>N<sub>4</sub>. α: absoption coefficient; hν: energy of incident photon.</p>
Full article ">Figure 8
<p>Thermogravimetric analysis (TGA) spectra of: (<b>a</b>) NiNPs; (<b>b</b>) g-C<sub>3</sub>N<sub>4</sub>; (<b>c</b>) g-PC<sub>3</sub>N<sub>4</sub>; (<b>d</b>) 5%Ni@g-PC<sub>3</sub>N<sub>4</sub>.</p>
Full article ">Figure 9
<p>Results of recycling experiments.</p>
Full article ">Scheme 1
<p>Reduction of nitrobenzenes on Ni@g-PC<sub>3</sub>N<sub>4</sub> (nickel nanoparticles grafted on P-doped g-C<sub>3</sub>N<sub>4</sub>) catalyst.</p>
Full article ">Scheme 2
<p>Synthetic illustration of Ni@g-PC<sub>3</sub>N<sub>4</sub> catalyst. NiNPs: nickel nanoparticles; BmimPF<sub>6</sub>: 1-butyl-3-methylimidazolium hexafluorophosphate.</p>
Full article ">Scheme 3
<p>Plausible mechanism on the basis of the band gap structure for the visible light reduction of nitrobenzenes by Ni@g-PC<sub>3</sub>N<sub>4</sub> photocatalyst. CB: conduction band; VB: valence band.</p>
Full article ">
2257 KiB  
Article
Ex-Vivo Tissues Engineering Modeling for Reconstructive Surgery Using Human Adult Adipose Stem Cells and Polymeric Nanostructured Matrix
by Francesco Morena, Chiara Argentati, Eleonora Calzoni, Marino Cordellini, Carla Emiliani, Francesco D’Angelo and Sabata Martino
Nanomaterials 2016, 6(4), 57; https://doi.org/10.3390/nano6040057 - 31 Mar 2016
Cited by 22 | Viewed by 6754
Abstract
The major challenge for stem cell translation regenerative medicine is the regeneration of damaged tissues by creating biological substitutes capable of recapitulating the missing function in the recipient host. Therefore, the current paradigm of tissue engineering strategies is the combination of a selected [...] Read more.
The major challenge for stem cell translation regenerative medicine is the regeneration of damaged tissues by creating biological substitutes capable of recapitulating the missing function in the recipient host. Therefore, the current paradigm of tissue engineering strategies is the combination of a selected stem cell type, based on their capability to differentiate toward committed cell lineages, and a biomaterial, that, due to own characteristics (e.g., chemical, electric, mechanical property, nano-topography, and nanostructured molecular components), could serve as active scaffold to generate a bio-hybrid tissue/organ. Thus, effort has been made on the generation of in vitro tissue engineering modeling. Here, we present an in vitro model where human adipose stem cells isolated from lipoaspirate adipose tissue and breast adipose tissue, cultured on polymeric INTEGRA® Meshed Bilayer Wound Matrix (selected based on conventional clinical applications) are evaluated for their potential application for reconstructive surgery toward bone and adipose tissue. We demonstrated that human adipose stem cells isolated from lipoaspirate and breast tissue have similar stemness properties and are suitable for tissue engineering applications. Finally, the overall results highlighted lipoaspirate adipose tissue as a good source for the generation of adult adipose stem cells. Full article
(This article belongs to the Special Issue Nanomaterials for Tissue Engineering)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>Isolation and characterization of hASCs (human adipose stem cells): L-ASCs (lipoaspirate-adipose stem cells) and B-ASCs (breast-adipose stem cells) were isolated from lipoaspirate adipose tissue and breast adipose tissue and cultured on TCP (tissue culture grade polystyrene) in growth medium. (<b>a</b>,<b>b</b>) Representative images of L-ASCs and B-ASCs showed the fibroblast-like morphology. Images were acquired with microscopy Eclipse-TE2000-S, Nikon (Nikon, Düsseldorf, Germany), using the F-ViewII FireWire<sup>TM</sup> camera (Olympus Soft Imaging System, Münster, Germany); (<b>c</b>,<b>d</b>) L-ASCs and B-ASCs have similar growth curve. Cells were harvested and counted by TRYPAN BLUE reagent (Sigma-Aldrich, St Louis, MO, USA) every 24 h for 20 days using a hemocytometer; (<b>e</b>,<b>f</b>) Mesenchymal stem cell phenotype of L-ASCs and B-ASCs was analyzed using a FACScan flow cytometry (BD Biosciences, San Jose, CA, USA), and FlowJo software (Tree Star, Ashland, OR, USA) for data management.</p>
Full article ">Figure 2
<p>L-ASCs and B-ASCs have multipotential property. <b>Panel A</b>: L-ASCs (<b>a</b>–<b>c</b>) and B-ASCs (<b>d</b>–<b>f</b>) incubated in osteogenic medium differentiated towards osteogenic lineage as demonstrated by the Alizarin Red staining (<b>a</b>,<b>d</b>) and calcium quantification (<b>c</b>,<b>f</b>); and (<b>b</b>,<b>e</b>) untreated cells. <b>Panel B</b>: L-ASCs (<b>g,h,i</b>) and B-ASCs (<b>j</b>,<b>k</b>,<b>l</b>) incubated in adipogenic medium differentiated towards adipogenic lineage as demonstrated by the OIL Red staining (<b>g</b>,<b>j</b>) and lipid quantification (<b>i</b>,<b>l</b>); and (<b>h</b>,<b>k</b>) untreated cells. Representative images were acquired with microscopy Eclipse-TE2000-S, Nikon, using the F-ViewII FireWire™ camera (Soft Imaging System, Olympus).</p>
Full article ">Figure 3
<p>L-ASCs and B-ASC cultured on INTEGRA<sup>®</sup> are hypo-immunogenic: L-ASCs (<b>a</b>) and B-ASC (<b>b</b>) cultured on INTEGRA<sup>®</sup> and TCP are hypo-immunogenic as demonstrated by an MLR (Mixed Lymphocyte Reaction) assay. Control, indicating positive proliferation of CD4<sup>+</sup>T-cells after co-culture on immunogenic PBMCs (peripheral blood mononuclear cell).</p>
Full article ">Figure 4
<p>INTEGRA<sup>®</sup> nanocomposite material is a suitable for culture of L-ASCs and B-ASCs. L-ASCs (<b>a</b>) and B-ASCs (<b>b</b>) cultured on INTEGRA<sup>®</sup> have similar viability to stem cells cultured on TCP as demonstrated by 2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide (XTT) assay measured at Absorbance (ABS) 450nm. L-ASCs (<b>c</b>,<b>d</b>) and B-ASCs (<b>e</b>,<b>f</b>) cultured on INTEGRA<sup>®</sup> maintained the fibroblast-like morphology. Representative images of cytoskeleton fibers (F-Actin, Tubulin), focal adhesion spot (Vinculin) and nuclei (DAPI: diamidino-2-phenylindole) were acquired with fluorescence microscopy Eclipse-TE2000-S, Nikon, using the F-ViewII FireWire<sup>TM</sup> camera (Soft Imaging System, Olympus).</p>
Full article ">Figure 5
<p>INTEGRA<sup>®</sup> nanocomposite material is suitable for tissue-engineering L-ASC- and B-ASC-modeling. Panel A: L-ASCs (<b>a</b>,<b>b</b>) and B-ASCs (<b>c</b>,<b>d</b>) cultured on INTEGRA<sup>®</sup> incubated in osteogenic medium differentiated towards osteogenic lineage as demonstrated by the Von Kossa staining (<b>a</b>,<b>c</b>) and Osteocalcin expression (<b>b</b>,<b>d</b>); and (<b>a’</b>–<b>d’</b>) untreated cells. Panel B: L-ASCs (<b>a</b>,<b>b</b>) and B-ASCs (<b>c</b>,<b>d</b>) cultured on INTEGRA<sup>®</sup> incubated in adipogenic medium differentiated towards adipogenic lineage as demonstrated by the Lipid Tox fluorescent staining; and (<b>a’</b>–<b>d’</b>). untreated cells. Representative images were acquired with fluorescence microscopy Eclipse-TE2000-S, Nikon) using the F-ViewII FireWire™ camera (Soft Imaging System, Olympus).</p>
Full article ">
164 KiB  
Editorial
Nanomaterials for Biosensing Applications
by Sichao Hou, Aiying Zhang and Ming Su
Nanomaterials 2016, 6(4), 58; https://doi.org/10.3390/nano6040058 - 30 Mar 2016
Cited by 47 | Viewed by 5255
Abstract
Nanomaterials have shown tremendous potentials to impact the broad field of biological sensing. Nanomaterials, with extremely small sizes and appropriate surface modifications, allow intimate interaction with target biomolecules. [...]
Full article
(This article belongs to the Special Issue Nanomaterials for Biosensing Applications)
1679 KiB  
Communication
Selective Labeling of Proteins on Living Cell Membranes Using Fluorescent Nanodiamond Probes
by Shingo Sotoma, Jun Iimura, Ryuji Igarashi, Koichiro M. Hirosawa, Hidenori Ohnishi, Shin Mizukami, Kazuya Kikuchi, Takahiro K. Fujiwara, Masahiro Shirakawa and Hidehito Tochio
Nanomaterials 2016, 6(4), 56; https://doi.org/10.3390/nano6040056 - 25 Mar 2016
Cited by 23 | Viewed by 8306
Abstract
The impeccable photostability of fluorescent nanodiamonds (FNDs) is an ideal property for use in fluorescence imaging of proteins in living cells. However, such an application requires highly specific labeling of the target proteins with FNDs. Furthermore, the surface of unmodified FNDs tends to [...] Read more.
The impeccable photostability of fluorescent nanodiamonds (FNDs) is an ideal property for use in fluorescence imaging of proteins in living cells. However, such an application requires highly specific labeling of the target proteins with FNDs. Furthermore, the surface of unmodified FNDs tends to adsorb biomolecules nonspecifically, which hinders the reliable targeting of proteins with FNDs. Here, we combined hyperbranched polyglycerol modification of FNDs with the β-lactamase-tag system to develop a strategy for selective imaging of the protein of interest in cells. The combination of these techniques enabled site-specific labeling of Interleukin-18 receptor alpha chain, a membrane receptor, with FNDs, which eventually enabled tracking of the diffusion trajectory of FND-labeled proteins on the membrane surface. Full article
(This article belongs to the Special Issue Nanoparticles in Bioimaging)
Show Figures

Figure 1

Figure 1
<p>(<b>a</b>) Bright field image, (<b>b</b>) fluorescence image, and (<b>c</b>) merge of human embryonic kidney 293 (HEK293) cells after staining with ampicillin-modified tetramethylrhodamine (TMR). Scale bar shows 50 µm.</p>
Full article ">Figure 2
<p>Fluorescence emission spectra of BL-tagged enhanced green fluorescent protein (BL-EGFP) (green), FND-HPG-Amp (red), and FND-HPG (blue) in Tris-HCl buffer after 2 h incubation with BL-EGFP and subsequent washing. Excitation wavelength was 488 nm. FND-HPG-Amp: fluorescent nanodiamond-hyperbranched polyglycerol-ampicillin; FND-HPG: fluorescent nanodiamond-hyperbranched polyglycerol; a.u.: arbitrary unit.</p>
Full article ">Figure 3
<p>(<b>a</b>) Fluorescence image of the surface of a single cell treated with FND-HPG-Amp particles. Bright red spots indicate the fluorescence from FNDs; (<b>b</b>) Molecule trajectories of two FND-labeled IL-18Rα recorded for <span class="html-italic">ca</span>. 8 s. The color code of the trajectory shows the time course, as indicated on the right side. Scale bar shows 10 μm. Movies are provided in <a href="#app1-nanomaterials-06-00056" class="html-app">supplementary material</a>.</p>
Full article ">Figure 4
<p>(<b>a</b>) Surface modification of fluorescent nanodiamonds (FNDs), FND-HPG: fluorescent nanodiamond-hyperbranched polyglycerol, HPG: hyperbranched polyglycerol, Amp: ampicillin, NHS: N-hydroxysuccinimide, WSC: water-soluble carbodiimide, FND-HPG-Amp: fluorescent nanodiamond-hyperbranched polyglycerol-ampicillin; (<b>b</b>) Scheme showing the specific labeling of Interleukin-18 receptor alpha (IL-18Rα) with FND using the BL-tag (β-lactamase-tag) system. HEK293 cell: human embryonic kidney 293 cell.</p>
Full article ">
2042 KiB  
Article
Numerical Study of Complementary Nanostructures for Light Trapping in Colloidal Quantum Dot Solar Cells
by Jue Wei, Qiuyang Xiong, Seyed Milad Mahpeykar and Xihua Wang
Nanomaterials 2016, 6(4), 55; https://doi.org/10.3390/nano6040055 - 25 Mar 2016
Cited by 11 | Viewed by 6845
Abstract
We have investigated two complementary nanostructures, nanocavity and nanopillar arrays, for light absorption enhancement in depleted heterojunction colloidal quantum dot (CQD) solar cells. A facile complementary fabrication process is demonstrated for patterning these nanostructures over the large area required for light trapping in [...] Read more.
We have investigated two complementary nanostructures, nanocavity and nanopillar arrays, for light absorption enhancement in depleted heterojunction colloidal quantum dot (CQD) solar cells. A facile complementary fabrication process is demonstrated for patterning these nanostructures over the large area required for light trapping in photovoltaic devices. The simulation results show that both proposed periodic nanostructures can effectively increase the light absorption in CQD layer of the solar cell throughout the near-infrared region where CQD solar cells typically exhibit weak light absorption. The complementary fabrication process for implementation of these nanostructures can pave the way for large-area, inexpensive light trapping implementation in nanostructured solar cells. Full article
(This article belongs to the Special Issue Nanostructured Solar Cells)
Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
<p>(<b>a</b>) The proposed process flow for fabrication of nanocavity and nanopillar arrays. (<b>b</b>) Top view scanning electron microscope (SEM) images and cross-sectional schematic of the nanocavity (left) and nanopillar (right) arrays fabricated using the proposed process.</p>
Full article ">Figure 2
<p>(<b>a</b>) Schematic of light diffraction in PbS quantum dot (QD) solar cell with patterned indium-doped tin oxide (ITO) electrode. (<b>b</b>) Optical constants of the materials used in the simulation model.</p>
Full article ">Figure 3
<p>The normalized transmission spectra of simulated patterned ITO structures: (<b>a</b>) nanocavity, (<b>b</b>) nanopillar. The plot shows the relative power transmitted into different diffracted orders and the net total transmitted power normalized to the simulation source power. Two of the strongest diffracted orders (1,1) and (2,0) are plotted. (0,0) represents the part of incident power not being diffracted by the structures.</p>
Full article ">Figure 4
<p>The light absorption spectra for PbS colloidal quantum dot (CQD) layer incorporated into different ITO structures normalized to (<b>a</b>) AM1.5G spectra and (<b>b</b>) simulation light source. The absorption enhancement for both cavity and pillar structures over the reference flat structure is obvious especially at resonance wavelengths of 950 nm for both structures and 1080 nm for cavity arrays. A slight absorption loss by ITO layer was also observed, as shown in <a href="#nanomaterials-06-00055-f004" class="html-fig">Figure 4</a>b.</p>
Full article ">Figure 5
<p>Simulated electric field distributions inside the PbS QDs layer with patterned structures. The hot spots present at resonance wavelengths (950 nm for both structures) with high field intensity indicate strong absorption inside PbS CQD. No hot spots are observed at off resonance wavelengths (1000 nm for both structures) suggesting the importance of resonant coupling of the incident into CQD layer for significant absorption enhancement.</p>
Full article ">
Previous Issue
Next Issue
Back to TopTop