|
Current
Nanoscience
ISSN: 1573-4137
Current Nanoscience
Volume 4, Number 3, August 2008
Contents
Morphology of C6 Glioma Cells on a Water-Repellent
Fractal Alkyl Ketene Dimer Surface Pp. 224-231
Wei-wei Hu, Hu Yan, Naoko Birukawa, Masashi
Abe, Etsuro Ito, Kaoru Tsujii, Zhong Chen and Akihisa
Urano
[Abstract]
Nano-Structured Materials in Plasmonics
and Photonics Pp. 232-235
Kosei Ueno, Yukie Yokota, Saulius Juodkazis,
Vygantas Mizeikis and Hiroaki Misawa
[Abstract]
Gas Sensing Properties of Au Modified SnO2
Micron Rods Pp. 236-239
Dong Xiaowen, Qin Lipeng, Xu Jiaqiang, Pan
Qingyi, Cheng Zhixuan and Xiang Qun
[Abstract]
The Different Bio-Effects of Functionalized Multi-Walled Carbon
Nanotubes on tetrahymena pyriformis Pp.
240-245
Jinxue Guo, Xiao Zhang, Shusheng Zhang,
Ying Zhu and Wenxin Li
[Abstract]
Investigation of the Oligonucleotide Nanosize
Delivery System with the Function of Targeting to Tumor Cells
Pp. 246-250
Zhenzhong Zhang, Xu Song, Baiyan Wang and
Huixiang Li
[Abstract]
Programming/Erasing Characteristics of Hysteresis-Based
Nonvolatile Memory Devices of Single-Wall Carbon Nanotubes
Pp. 251-255
Ao Guo, Yunyi Fu, Lunhui Guan, Jia Liu,
Chuan Wang, Falong Zhou, Zujin Shi, Zhennan Gu, Ru Huang
and Xing Zhang
[Abstract]
Nano-Scale Analysis Using Synchrotron-Radiation:
Applications in the Semiconductor Industry Pp. 256-266
Ehrenfried Zschech, Holm Geisler, Jochen
Rinderknecht, Gerd Schneider, Ralph Spolenak and Dieter
Schmeisser
[Abstract]
Novel PEGylated PPI Dendritic Nanostructures for
Sustained Delivery of Anti-Inflammatory Agent Pp.
267-277
Virendra Gajbhiye, P. Vijayaraj Kumar, Ajay
Sharma and N.K. Jain
[Abstract]
Nanoparticles in the Environment as Revealed by
Transmission Electron Microscopy: Detection, Characterisation
and Activities Pp. 278-301
Gary G. Leppard
[Abstract]
Magnetic Nanoparticles Utilized in Hemodialysis
for the Treatment of Hyperhomocysteinemia: The New Challenge
of Nanobiotechnology Pp. 302-307
D. Stamopoulos
[Abstract]
Confined Photoreaction in Nano-Engineered Multilayer
Microshells Pp. 308-313
Xia Tao and Jingmei Su
[Abstract]
Abstracts
[Back to top]
Morphology of C6 Glioma Cells on a Water-Repellent Fractal
Alkyl Ketene Dimer Surface
Wei-wei Hu, Hu Yan, Naoko Birukawa, Masashi
Abe, Etsuro Ito, Kaoru Tsujii, Zhong Chen and Akihisa
Urano
In many in vitro cultures, cells may change
their morphology, probably caused by adherence to the surface
of the culture dish. Since a fractal alkyl ketene dimer (AKD)
surface provides super water-repellency with a contact angle
of 174°, we considered that it might provide an improved
surface environment for the growth and differentiation of
cells by preventing intimate adhesion. C6 glioma cells which
were selected to test the effects of the fractal surface,
were cultured on a conventional surface, a smooth AKD surface
or a fractal AKD surface. On the conventional and smooth AKD
surfaces, cells developed bipolar or multipolar shapes with
enlarged cell bodies and neurite-like processes. In contrast,
cells cultured on the fractal AKD surface presented fine filopodium-like
processes like protoplasmic astrocytes in vivo, and
higher morphological complexity was revealed by fractal analysis.
Reconstruction of three-dimensional shape indicated that cells
on the fractal surface were globular, whereas those on the
conventional surface were rather flat. Our results suggest
that C6 glioma cells on a fractal AKD surface show features
of natural astrocytes with their elaborate morphology. The
fractal surface thus may provide a new and natural culture
environment for experimental assessment of glial structure
and function.
[Back to top]
Nano-Structured Materials in Plasmonics
and Photonics
Kosei Ueno, Yukie Yokota, Saulius Juodkazis,
Vygantas Mizeikis and Hiroaki Misawa
We investigate functional capabilities of large arrays of
gold and silver nanorods as elements of plasmonic devices.
The samples were fabricated by electron beam lithography and
lift-off techniques on glass substrates. The areas patterned
by the nanorods or other nanoparticles can be large, with
dimensions of up to about one centimeter. Structural and optical
characterization has allowed confirmation of a high homogeneity
of the fabricated ensembles of nanorods, and a high sensitivity
of their longitudinal extinction bands to the variations of
the nanorod length and the refractive index of the environment.
Applications of nanorods as refractive-index sensors is discussed.
[Back to top]
Gas Sensing Properties of Au Modified SnO2
Micron Rods
Dong Xiaowen, Qin Lipeng, Xu Jiaqiang, Pan
Qingyi, Cheng Zhixuan and Xiang Qun
SnO2 micron rods were prepared
via a simple solution phase precursor route and modified with
1 wt% of Au. The products are characterized by X-ray diffraction
(XRD) and scanning electron microscopy (SEM). The gas sensing
properties of the materials were tested in an organic glass
chamber by mixing target gas into air. The results revealed
that the product consists of SnO2
micron rods with diameters of ~1-3 µm and lengths of
~15-25 μm.
SnO2 micron rods gas sensors
exhibit good sensitivity and stability. Compared with pure
SnO2 powders, the surface
Au sensitization can improve the sensitivity and selectivity
of the sensors. The role of Au in SnO2
gas sensor belongs to electronic sensitization. Large-scale
synthesis and good sensitivities of SnO2
micron rods indicate the potential applications in gas sensors
at the industry level.
[Back to top]
The Different Bio-Effects of Functionalized Multi-Walled Carbon
Nanotubes on tetrahymena pyriformis
Jinxue Guo, Xiao Zhang, Shusheng Zhang,
Ying Zhu and Wenxin Li
To promote the applications of namomaterials, the potential
toxicity of multi-walled carbon nanotubes (MWCNTs) and their
derivates to environment have been studied. With γ-ray
irradiation, MWCNTs were modified chemically with glucosamine
and decylamine to obtain glucosamine-MWCNTs (g-MWCNTs) and
decylamine-MWCNTs (d-MWCNTs). Their toxicological experiments
were carried out with Tetrahymena pyriformis. The
results illustrate that d-MWCNTs show a dose-dependent growth
inhibition to the cells, due to the increasing concentration
of toxic decylamine. This was attributed to the biological
function performed by the decylamine after it was carried
into the cell interior by the tubes MWC. The results have
a certain reference value for the applications ofNTs used
as drug delivery system. Both glucosamine and purified MWCNTs
(p-MWCNTs) alone show little biological activity, but g-MWCNTs
exhibit a dose-dependent growth stimulation. This is due to
the fact that the increasing hydrophilicity of g-MWCNTs promotes
the conjugation of nanotubes with soluble peptone in culture
medium via noncovalent binding. Uptake of the g-MWCNTs-peptone
conjugates with various concentration of peptone by the cells
is responsible for the dose-dependent growth stimulation.
Consequently we propose the effects of concentration of functional
groups, hydrophilicity of functionalized nanotubes as well
as sequential nonspecific interaction between nanotubes with
some components in culture medium on living system should
be taken into account in the study of cytotoxicity of carbon
nanotubes.
[Back to top]
Investigation of the Oligonucleotide Nanosize
Delivery System with the Function of Targeting to Tumor Cells
Zhenzhong Zhang, Xu Song, Baiyan Wang and
Huixiang Li
The effects of the tested factors including pH value, NaCl
concentration, ODN concentration and charge ratio on the size
and zeta potentials of nanoparticles (ODN-PLL, PLL: poly(l-lysine)s)
were investigated by use of uniform design and NGR peptides
were used to modify the nanoparticles, indicating that none
of the tested factors was correlated with nanoparticles’
size, however, a linear correlation (r = 0.8505)
was found between charge ratio and zeta potential. A nanosize
delivery system (ODN-PLL-NGR) with the function of targeting
to tumor cells was developed by use of PLL to condense oligonucleotide
into nanoparticles coated with peptide containing NGR motif.
The ODN-PLL-NGR had the ability to protect ODN against nuclease
degradation, and its cell uptake increased with time increment
after incubation at 37 °C for 40, 50 and 60 min.
[Back to top]
Programming/Erasing Characteristics of Hysteresis-Based
Nonvolatile Memory Devices of Single-Wall Carbon Nanotubes
Ao Guo, Yunyi Fu, Lunhui Guan, Jia Liu,
Chuan Wang, Falong Zhou, Zujin Shi, Zhennan Gu, Ru Huang
and Xing Zhang
Hysteresis effect in carbon nanotube field-effect transistors
can be commonly employed to construct the nonvolatile memory
devices of single-wall carbon nanotubes. In this paper, we
investigate in detail the programming/erasing characteristics
of such memory devices, which may present great importance
for their availabilities. In order to write and erase the
memory devices with reproducibility and stability, it is essential
to set the writing and erasing time appropriately. The writing
and erasing process of such memory devices is, in general,
found to be much slower compared with traditional CMOS memory
devices, typically operating on a time scale of the order
of a second, which may pose a serious challenge to their practical
exploitation. Furthermore, the stability of charge storage
in such memories is slightly affected by temperature. A model
based on electric polarization of surface-bound water molecules
on SiO2 insulator has also been proposed to explain qualitatively
the hysteresis and memory effect of these devices.
[Back to top]
Nano-Scale Analysis Using Synchrotron-Radiation:
Applications in the Semiconductor Industry
Ehrenfried Zschech, Holm Geisler, Jochen
Rinderknecht, Gerd Schneider, Ralph Spolenak and Dieter
Schmeisser
In semiconductor industry, process control and physical failure
analysis were dominated by light and electron microscopy as
well as surface analysis techniques including X-ray photoelectron
spectroscopy (XPS) until the end of the last century. During
the past decade, X-ray diffraction (XRD) and X-ray reflectivity
(XRR) have been successfully applied in out-of-fab analytical
labs. In addition to XRF and TXRF, some additional X-ray techniques
– e.g. XRD, XRR and XPS - have been moved or are in
the process to be moved from lab-based studies to in-line
applications, using cleanroom compatible thin film characterization
tools in wafer fabs. Lab-based smallangle X-ray scattering
(SAXS) tools are applicable for pore size characterization
in porous thin films. Advanced transmission X-ray microscopy
(TXM) and X-ray computed tomography (XCT) systems with sub-100
nm resolution are currently being evaluated for their use
in out-of-fab analytical labs. Apart from the on-site use
of laboratory X-ray sources, synchrotron-radiation sources
have been used in all fields of X-ray techniques: diffraction
(SR-XRD), spectroscopy (SR-XPS, XAFS) and microscopy (SR-TXM/XCT).
The high brightness and collimation of SR beams provide unique
possibilities, e.g. for in-situ X-ray microdiffraction, photoelectron
emission microscopy (PEEM) and in-situ TXM/XCT.
In this paper, we demonstrate the high potential of the X-ray
techniques for semiconductor industry, we describe potential
implementations of these techniques for current and future
applications, particularly for advanced process development
and process monitoring, and we provide an outlook showing
that we are living in a decade which is characterized by a
breakthrough in the industrial application of X-ray techniques.
The application focus of this review is on the study of two
types of nanostructures with typical dimensions less than
100 nm: artificial nanolayers and nanostructures caused by
thin film deposition and patterning (litho/etch) processes
as well as nanostructured materials, i. e. thin film materials
with a “sub-structure” on sub-100 nm length scale.
[Back to top]
Novel PEGylated PPI Dendritic Nanostructures for
Sustained Delivery of Anti-Inflammatory Agent
Virendra Gajbhiye, P. Vijayaraj Kumar, Ajay
Sharma and N.K. Jain
The present study was aimed at developing and exploring the
use of long circulating biocompatible PEGylated PPI 5.0G dendrimers
for delivery of an anti-inflammatory drug, Aceclofenac. The
PPI 5.0G dendrimers were synthesized and PEGylated using N-hydroxysuccinimide-activated
dicarboxylic acid PEG 2000 (COOH-PEG-COOH). PEGylation was
confirmed by IR, NMR and MASS spectra. The Aceclofenac was
loaded in PEGylated dendritic system and various parameters
like, hemolytic toxicity, drug entrapment, pH dependent in
vitro drug release and in vivo blood-level were
determined. The PEGylated dendritic system has shown increased
drug-loading capacity and reduced hemolytic toxicity as compared
to non-PEGylated system. The in vitro release, in
vivo blood level and tissue distribution studies in albino
rats demonstrated suitability of PEGylated PPI 5.0G dendrimer
for prolonged delivery of Aceclofenac. The carrageenan induced
paw edema in albino rats revealed 69.41±0.7% and 77.08±0.4%
inhibition of paw edema at 3rd
and 7th hr, respectively
that were maintained upto 52.17±0.9% until 48th
hr from drug-PEGylated dendrimer complex. However, for plain
drug the percentage of inhibition were found to be 66. 35±0.4%
at 3rd hr, which was reduced
to 28.44±0.3 % by 7th
hr. PEGylation is considered to be suitable for amendment
of PPI dendrimers for reducing of drug leakage and hemolytic
toxicity, improving drug-loading capacity and stabilizes the
system in body. The results suggested that, such PEGylated
dendrimeric system is suitable for sustained delivery of Aceclofenac.
[Back to top]
Nanoparticles in the Environment as Revealed by
Transmission Electron Microscopy: Detection, Characterisation
and Activities
Gary G. Leppard
The characterisation of natural aquatic nanoparticles
(especially in relation to flocculation processes, contaminant
transport and biogeochemistry) has become an important field
of environmental science. Ubiquitous colloid-size microbes
and their nanoscale extracellular components affect the chemistry
and physical properties of their surroundings in all habitable
environments on Earth, thus affecting fundamentally the planet’s
geochemical systems. The adverse health effects of airborne
particles, and the atmospheric deposition of particulate contaminants
into surface waters, are well recognised environmental issues,
with serious questions being posed about the biomedical effects
of the nanoparticle component. There is a growing public health
concern about nanoparticles in general, as a result of biomedical
findings which reveal that atmospheric nanoparticles can present
unanticipated toxicity and mechanisms for entering biological
cells. The evolving analytical needs, issues, concerns and
new facts call for improved means to detect and characterise
environmental nanoparticles. Transmission electron microscopy
(TEM) is making a major contribution. With foci on aquatic
and airborne examples, this review presents literature highlighting
nanoparticle relevance to environmental and public health.
Common "species" of nanoparticles are described,
while characterisation by TEM is considered in terms of apparatus,
artifact minimisation and standard protocols for isolation
and concentration. Evolving correlative microscopical approaches
to characterisation are outlined, along with successful case
studies involving heterogeneous environmental samples. Diverse
activities of aquatic nanoparticles are featured, with reference
to planetary-scale biogeochemical processes and water treatment.
Informed speculation is presented on upcoming improvements
to nanoparticle characterisation.
[Back to top]
Magnetic Nanoparticles Utilized in Hemodialysis
for the Treatment of Hyperhomocysteinemia: The New Challenge
of Nanobiotechnology
D. Stamopoulos
Owing to vast technological advances, hemodialysis (HD)
has become a mature modality significantly increasing the
survival of end-stage renal disease (ESRD) patients. However,
many HD complications still exist that mainly relate to the
nature of middle-molecular-weight and/or protein-bound toxins
that both low- and high-flux dialysers cannot efficiently
remove. For instance, hyperhomocysteinemia and amyloidosis
are two dialysis-related disorders that motivate serious health
complications. Here, we introduce a new method for the selective
removal of specific toxins that is based on the preparation
of Ferromagnetic Nanoparticle-Targeted Binding Substance Conjugates
(FN-TBS Cs) constituted of biocompatible FNs and a specifically
designed TBS that must have high affinity for the respective
Target Toxin Substance (TTS). The FN-TBS Cs should be administered
to the patient timely prior to the dialysis session so that
they will be able to bind with the specific TTS owing to their
free circulation in the bloodstream. The complex FN-TBS-TTS
can be selectively removed from the ESRD patient during the
HD session by means of a magnetic dialyser (MD). For the in
vitro evaluation of this proposal we employed highly
biocompatible Fe3O4
and Bovine Serum Albumin (BSA) as constituents of the FN-TBS
Cs and an array of permanent magnets placed along the circulation
line as a simple MD. We have evaluated the binding affinity
and capacity of both bare Fe3
O4 FNs and Fe3
O4-BSA Cs by
employing homocysteine (Hcy) as a model TTS. We investigate
Hcy concentrations ranging from mild to severe hyperhomocysteinemia.
Most importantly, we investigate the effectiveness of low
concentrations of Fe3O4
that are within the safety levels established from the treatment
of iron-deficiency anemia, thus making a preliminary evaluation
of future in vivo applications. We observed that
Hcy is readily adsorbed onto both bare Fe3
O4 FNs and Fe3
O4-BSA Cs. The obtained results
prove the successful in vitro applicability of the
proposed method since pathological Hcy concentrations may
be adequately handled by relatively low Fe3
O4 concentrations, thus making
feasible future in vivo applications.
[Back to top]
Confined Photoreaction in Nano-Engineered Multilayer
Microshells
Xia Tao and Jingmei Su
Nano-engineered multilayer microshells (microcapsules)
as nano/microreactors are expected to expand the capabilities
of confined photoreaction occurring in shell walls and in
shell interiors and to explore new functionalities of application.
The basis for optical reactions in multilayer microshells
is their tailored wall components and particular properties
originated from the permeability and stability of shell walls
in response to external stimuli. This review aims at describing
recent developments on the photochemical behaviors of photofunctionalized
shell walls, mainly focusing on photocontrollable wall permeability
by visible illumination. Apart from these, the photocatalytic
reaction in spatially confined microshells is also reviewed,
with an emphasis on recent advances in the visible light-assisted
degradation of defined dye pollutants in the homogeneous or
heterogeneous photo-Fenton system. The photoreaction mechanism
occurring in the shells is also discussed. Finally, we have
addressed some of the perspectives and challenges for the
potential future development of microshells as photoreactors
and applications based on these systems.
|
