| Current
Nanoscience
ISSN: 1573-4137
Current Nanoscience
Volume 3, Number 2, May 2007
Contents
Biological Assembly of Hybrid Inorganic Nanomaterials
Pp. 117-120
Joseph M. Slocik and Rajesh R. Naik
[Abstract]
Analytical Characterisation of Pd/ZrO2
Composite Nanoparticles Employed in Heterogeneous Catalysis
Pp. 121-127
N. Cioffi, M. Faticanti, N. Ditaranto, S. De Rossi, L.
Traversa, A. Monopoli, A. Nacci, L. Torsi and L. Sabbatini
[Abstract]
Electric Bio-Chips for Rapid and Quantitative Detection
of Specific Biological Materials Pp. 129-133
[Abstract]
Structure of the Nanoscience and Nanotechnology Instrumentation
Literature Pp. 135-154
Ronald N. Kostoff, Raymond G. Koytcheff and Clifford G.Y.
Lau
[Abstract]
Fabrication and Electrochemical Characterization of
Molecularly Alternating Self-Assembled Films and Capsules
of Titania Nanosheets and Gold Nanoparticles Pp.
155-160
Yong Zhou, Lian Z. Wang, Ren Z. Ma, Yasuo Ebina, Kazunori
Takada and Takayoshi Sasaki
[Abstract]
DNA Electronics: A Nanotechnology Approach
Pp. 161-165
S. A. Patil, V. S. Gomase and K.V. Kale
[Abstract]
Polarized Angular Dependent Light Scattering Properties
of Bare and PEGylated Gold Nanoshells Pp. 167-170
Kun Fu, Jiantang Sun, Alex W. H. Lin, Hui Wang, Naomi
J. Halas and Rebekah A. Drezek
[Abstract]
Microwave-Assisted Synthesis of Magnetite Nanosheets
in Mixed Solvents of Ethylene Glycol and Water Pp.
171-176
Wei-Wei Wang and Ying-Jie Zhu
[Abstract]
Ostwald Ripening: A Synthetic Approach for Hollow
Nanomaterials Pp. 177-181
Hua Chun Zeng
[Abstract]
Application of Nanoparticles in Oral Delivery of Immediate
Release Formulations Pp. 183-190
Filippos Kesisoglou, Santipharp Panmai and Yunhui Wu
[Abstract]
Improved Bioavailability of Albendazole Following
Oral Administration of Nanosuspension in Rats Pp.
191-194
Mittapalli Pavan Kumar, Yamasani Madhusudan Rao and Shashank
Apte
[Abstract]
Abstracts
[Back to top]
Biological Assembly of Hybrid Inorganic Nanomaterials
Joseph M. Slocik and Rajesh R. Naik
The assembly of two or more inorganic nanoparticles results
in hybrid materials with enhanced properties. These include
improvements in catalytic activity, changes in optical behavior,
and potential gains in electronic properties. However, these
are only attained through precise synthetic control of the
resulting material with respect to structure, organization,
size, and composition. Fortunately, biological systems are
exceptional at the synthesis and assembly of diverse inorganic
materials at many different length scales; and as result,
has inspired many different approaches towards the biomimetic
synthesis of hybrid inorganic materials.
[Back to top]
Analytical Characterisation of Pd/ZrO2
Composite Nanoparticles Employed in Heterogeneous Catalysis
N. Cioffi, M. Faticanti, N. Ditaranto, S. De Rossi, L.
Traversa, A. Monopoli, A. Nacci, L. Torsi and L. Sabbatini
Pd/ZrO2 nanocomposite materials were synthesised
following a two-step procedure. Firstly, tetragonal zirconia
was prepared via a chemical route; then it was subjected to
an in-situ electrochemical impregnation with palladium nanoparticles.
Different process times lead to a different Pd loading in
the resulting material. Pd/ZrO2 powders were subjected
to morphological and spectroscopic characterisation. Transmission
electron microscopy (TEM) analysis showed that ZrO2
nanograins have an average size of 150±70nm, and are
composed of smaller sub-grains (average diameter = 40±10
nm). Spherical Pd nanoparticles are evenly dispersed on the
oxide support, their average core diameter being 6.9±1.8
nm. X-ray Photoelectron Spectroscopy (XPS) was used to asses
the materials surface chemical composition. Testing the catalysts
for the CO oxidation revealed an appreciable activity of the
Pd-modified ZrO2 samples. TEM and XPS analyses
were also performed on materials exposed to prolonged catalytic
runs and contributed to shed light on the catalysis mechanism.
A rationale for the results obtained on the CO conversion
process was proposed, invoking a key- catalytic role of finely
dispersed PdO sites. The nanomaterial morphological stability
and reactivity encouraged to employ it in the Heck synthesis
of butyl cinnamate. This process was demonstrated to take
place with high conversion values and interesting stability
towards catalyst recycling.
[Back to top]
Electric Bio-Chips for Rapid and Quantitative Detection
of Specific Biological Materials
Although many sophisticated methods for specific detection
of a biological material (from cells, through viruses to nucleic
acids and proteins) are available, there is still a need for
their improvement. Particularly, an optimal method should
be sensitive, rapid and quantitative. However, it appears
that traditional molecular biology procedures are often either
too long or semi-quantitative at best. This makes particular
problems in medical and biotechnological approaches, where
rapid and quantitative assays are required for either detection
of specific pathogens or continuous monitoring of biotechnological
processes (e.g. production of certain components by microbes
in bio-reactors or detection of bacteriophage contamination
in bacterial cultures). In this review, we present a recently
developed nano-technique of electric bio-chips, which appears
to be suitable for rapid and quantitative detection of various
biological materials. One of variants of this technique is
based on miniaturized amperometric biosensor devices that
enable evaluation of biomolecular interactions by measuring
the redox recycling of enzymatic reaction products. Electric
bio-chips were reported to be useful for detection and quantification
of both biological macromolecules (nucleic acids and proteins)
and microorganisms (bacteria and viruses). Thus, it appears
that this technique may be successfully employed in various
bio-medical and biotechnological applications.
[Back to top]
Structure of the Nanoscience and Nanotechnology Instrumentation
Literature
Ronald N. Kostoff, Raymond G. Koytcheff and Clifford G.Y.
Lau
The instrumentation literature associated with nanoscience
and nanotechnology research was examined. About 65000 nanotechnology
records for 2005 were retrieved from the Science Citation
Index/ Social Science Citation Index (SCI/SSCI) [1], and ~27000
of those were identified as instrumentation-related. All the
diverse instruments were identified, and the relationships
among the instruments, and among the instruments and the quantities
they measure, were obtained. Metrics associated with research
literatures for specific instruments/ instrument groups were
generated.
[Back to top]
Fabrication and Electrochemical Characterization of
Molecularly Alternating Self-Assembled Films and Capsules
of Titania Nanosheets and Gold Nanoparticles
Yong Zhou, Lian Z. Wang, Ren Z. Ma, Yasuo Ebina, Kazunori
Takada and Takayoshi Sasaki
A molecularly alternating self-assembled film and heterostructured
capsule of titania nanosheets/gold nanoparticles has been
successfully fabricated by layer-by-layer self-assembly of
titania nanosheets and positively charged gold nanoparticles
as electrostatic building blocks. The films were characterized
with atomic force microscopy and UV-vis absorption spectroscopy.
The nearly linear increase in both UV-vis absorbances as a
function of the sequential assembly number demonstrates the
regular growth of the composite film. The electrochemcial
property of the fabricated (titania nanosheet/Au nanoparticle)n
multilayer film was examined by measuring cyclic voltammograms.
The heterostructured capsule from a UV-sensitive poly(methyl
methacrylate) as a sacrificial template was characterized
by field-emission scanning electron microscopy and transmission
electron microscopy. The energy-dispersive X-ray spectrometer
verifies the composition of Ti and Au elements of the heterostructured
capsule.
[Back to top]
DNA Electronics: A Nanotechnology Approach
S. A. Patil, V. S. Gomase and K.V. Kale
DNA, the blueprint of life, has taken centre stage in biological
research during the past few decades. DNA plays an important
role in molecular biology as the carrier of genetic information
in all living species. Bio-physicists and chemists have become
increasingly interested in the electronic properties of the
"molecule of life"; DNA. Experiments are now starting
to provide the first clues about the mechanisms that underlie
charge transport in DNA. They sparked the creation of whole
new industries based on this knowledge and on the various
biotools and technologies that have subsequently developed.
Biologically, the well-known function of DNA is to code for
functional proteins that are the expressed form of hereditary,
genetic information. But in the past few years, the discovery
that DNA can conduct an electrical current has made it an
interesting molecule for other roles that nature did not intend
for this molecule. DNA could be useful in nanotechnology for
the design of electronic circuits, which could help to overcome
the limitations that classical silicon-based electronics is
facing in the coming years.
[Back to top]
Polarized Angular Dependent Light Scattering Properties
of Bare and PEGylated Gold Nanoshells
Kun Fu, Jiantang Sun, Alex W. H. Lin, Hui Wang, Naomi
J. Halas and Rebekah A. Drezek
Metal nanoshells have found promising applications in biomedical
imaging and cancer therapy. To facilitate the application
of nanoshells in scattering based imaging techniques, it is
essential to characterize their light scattering properties.
We have studied the light scattering from nanoshells at the
quadrupolar and octupolar frequencies of the surface plasmon
resonance, and our measurements are in good agreement with
Mie theory calculations for both wavelengths. For in vivo
use of nanoparticles in biomedical imaging and therapy, surface
modification is of great importance in enhancing the stability
and biocompatibility of these particles, and polyethylene
glycol is commonly used for the surface modification of metal
and semiconductor nanoparticles. However, the influence of
surface modification on the optical properties of nanoparticles
has not been systematically studied yet. Here, we also report
the study on the polarized and angularly-resolved light scattering
properties of gold nanoshells before and after polyethylene
glycol modification. We find that polyethylene glycol does
not influence the extinction profile of gold nanoshells. Furthermore,
there is no significant change in the scattering phase function
of nanoshells after polyethylene glycol modification.
[Back to top]
Microwave-Assisted Synthesis of Magnetite Nanosheets
in Mixed Solvents of Ethylene Glycol and Water
Wei-Wei Wang and Ying-Jie Zhu
Magnetite (Fe3O4) nanosheets have been
prepared by a simple microwave heating method using ferrous
sulfate and sodium hydroxide in mixed solvents of ethylene
glycol and water. Fe3O4 nanosheets were
obtained by the oxidation of the deep green precursor with
the sheet morphology in an alkaline solution. Our experiments
show that iron salt, the ratio of OH to iron ions and the
heating method have effects on the morphology or crystalline
phase of Fe3O4. Both Fe3O4
nanosheets and nanoparticles exhibit a small hysteresis loop
at room temperature. The saturation magnetization of Fe3O4
nanosheets is smaller than that of Fe3O4
nanoparticles.
[Back to top]
Ostwald Ripening: A Synthetic Approach for Hollow
Nanomaterials
Hua Chun Zeng
Fabrication of nanomaterials with hollow interiors is an important
research area in nanoresearch, owing to their potential applications
in photonic devices, drug delivery, material encapsulation,
ionic intercalation, surface functionalization, nanocatalysts,
membrane nanoreactors, and many other technologies. The common
preparative methods for this new class of materials can be
broadly divided into hard and soft template-assisted syntheses.
In recent years, furthermore, the interest in template-free
techniques for these materials has also increased, as the
new processes involved in these techniques are relatively
simple and less demanding, compared to the template-assisted
processes. In this short review, we will introduce the application
of a well-known physical phenomenon of crystal growth –
Ostwald ripening – in the fabrication of hollow nanomaterials.
It has been demonstrated that formation of the interior spaces
of nanostructures depends on the aggregative states of the
primary crystallites during the synthesis. With this new development,
many inorganic nanomaterials with interior spaces can now
be fabricated in solution media together with the materials
synthesis. Different types of Ostwald ripening observed in
this synthetic approach have been reviewed. In particular,
various geometric structures and configurations prepared with
these methods have been discussed. The prepared hollow materials
also allow further compositional and structural modifi-cations
under the similar process conditions. Future directions in
this research area are also discussed.
[Back to top]
Application of Nanoparticles in Oral Delivery of Immediate
Release Formulations
Filippos Kesisoglou, Santipharp Panmai and Yunhui Wu
An increasing percentage of drug development candidates suffer
from poor aqueous solubility which in turn often times leads
to poor oral absorption. This poses significant challenges
in formulation development to ensure bioavailability following
oral administration. Traditional approaches to increase dissolution
of immediate release formulations include incorporation of
surfactants, reduction of particle size and liquid vehicle
formulations. More recently, size reduction of either the
active pharmaceutical ingredient (API) particle or the drug
delivery system down to the sub-micron range appears as a
new promising approach to further increase dissolution rates
of hydrophobic molecules. Nanonization of either the API,
in the form of nanosuspensions typically stabilized with surfactants,
or of the formulation vehicle such as with the use of self-nanoemulsified
drug delivery systems and solid lipid nanoparticles has been
successfully utilized to increase in vivo dissolution.
Such nanotechnology has demonstrated significant impact on
enhancing the bioavailability of drug candidates and addressing
issues such as inadequate exposure or food effect. The goal
of this review is to summarize recent advances in the utilization
of nanosuspensions, solid lipid nanoparticles or nanoemulsions
in drug delivery of immediate release dosage forms.
[Back to top]
Improved Bioavailability of Albendazole Following
Oral Administration of Nanosuspension in Rats
Mittapalli Pavan Kumar, Yamasani Madhusudan Rao and Shashank
Apte
Albendazole, a lipophilic anthelmintic drug, has low solubility
and bioavailability. Albendazole nanosuspensions (ABZNS) were
developed using different surfactants (Polysorbate 80 &
Poloxamer 188) and hydrophilic mucoadhesive polymers (Hydroxypropyl
Methylcellulose) by pre-homogenization followed by high pressure
homogenization. Particle size and charge measurements were
made with a Malvern Zetasizer. Pharmacokinetics of optimized
albendazole nanosuspensions after oral administration to conscious
Wistar rats was studied. Average size and zeta potential of
optimized formulations of albendazole nanosuspensions ranged
from 385.7± 4.3 to 576.2 ± 4.8 nm and - 23.5
± 1.8 to - 40.5 ± 0.8 mV, respectively. Bioavailability
of albendazole nanosuspensions was 2.14 to 2.96 fold after
oral administration compared with that of control suspension.
These results indicate the potential of nanosuspension in
improvement of oral bioavailability of lipophilic drugs such
as albendazole.
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