| Current
Nanoscience
ISSN: 1573-4137
Current Nanoscience
Volume 2, Number 1, February 2006
Contents
Chemically Modified Nano Crystalline Diamond
Layer as Material Enhanced Laser Desorption Ionisation (MELDI)
Surface in Protein Profiling Pp. 1-7
M. Najam-ul-Haq, M. Rainer, C. W. Huck, G. Stecher, I.
Feuerstein, D. Steinmüller and G.K. Bonn
[Abstract]
Effect of Surface Oxides and Intermetallics on Nanostructured
Diamond Coating of Nitinol Pp. 9-12
Shane A. Catledge, Vinoy Thomas and Yogesh K. Vohra
[Abstract]
Chemical-Solution Deposition of Hafnia Films on Self-Assembled
Molecular Monolayers Pp. 13-32
Michael Z. Hu, Amy C. DeBaillie, Yayi Wei and Gerold E.
Jellison
[Abstract]
Electron Transfer and Nano-Scale Motions in Nitrogenase
Fe-Protein Pp. 33-41
Mi Suk Jeong and Se Bok Jang
[Abstract]
Nanomagnets-From Fundamental Physics to Biomedicine
Pp. 43-53
Pedro Tartaj
[Abstract]
Liposomes as Vehicles for Enhancing Drug Delivery
Via Skin Routes Pp. 55-70
Jia-You Fang, Tsong-Long Hwang and Yen-Ling Huang
[Abstract]
One Dimensional Nanomaterials: Preparation, Structures,
and Assembly Pp. 71-88
Yingjun Liu, Zuwei Ma and Seeram Ramakrishna
[Abstract]
Abstracts
[Back to top]
Chemically Modified Nano Crystalline Diamond Layer
as Material Enhanced Laser Desorption Ionisation (MELDI) Surface
in Protein Profiling
M. Najam-ul-Haq, M. Rainer, C. W. Huck, G. Stecher, I.
Feuerstein, D. Steinmüller and G.K. Bonn
The discovery and utility of new methods based on different
materials and chemical derivatisations for protein profiling
of complex analytes is an ongoing field. This study includes
the development, optimisation, validation and the application
of a method based on the combined characteristics of physisorption
and chemisorption of nano crystalline diamond (NCD) surfaces
for serum profiling. Due to the expanded nano-structure, the
numbers of potential binding sites are dramatically increased.
For immobilised metal ion affinity chromatography (IMAC),
diamond coated surfaces were derivatised with glycidyl methacrylate
(GMA) under ultraviolet (UV) light at different wavelengths
followed by further derivatisation with iminodiacetic acid
(IDA) and loading with copper ions. This special kind of MALDI/TOF-MS,
was termed as MELDI/TOF-MS (Material enhanced laser desorption
ionization time of flight mass spectrometry), as it is based
on various materials e.g. diamond, cellulose, silica and poly
(glycidyl methacrylate/divinylbenzene). The diversity in the
physical characteristics of these derivatised materials is
responsible to get improved sensitivity, specificity, capacity
and broad range of information. Human serum samples were assayed
through MELDI/TOF-MS analysis to validate the capability,
capacity, efficiency and reproducibility of the nano-structured
diamond surfaces for protein profiling. Also the method was
employed to search for the differences in human body fluids
e.g. sera of different origin through matrix assisted laser
desorption ionisation time of flight mass spectrometry (MALDI/TOF-MS).
[Back to top]
Effect of Surface Oxides and Intermetallics on Nanostructured
Diamond Coating of Nitinol
Shane A. Catledge, Vinoy Thomas and Yogesh K. Vohra
Microwave plasma chemical vapor deposition (CVD) was used
to grow nanostructured diamond onto mechanically polished
superelastic Nitinol (NiTi) alloy. As determined by glancing-angle
x-ray diffraction, mechanical polishing of the heavily oxidized
as-received samples resulted in removal of nickel, Ni3Ti,
and TiO2 surface phases, leaving the NiTi austenite
(B2 type, CsCl structure) to be detected. Diamond nucleation
and growth was impractically slow on the mechanically polished
samples and could only yield continuous films at practical
growth rates when they were first exposed to plasma annealing
to allow formation of oxide and intermetallic phases (Ni3Ti,
NiTi,2). The ability of a surface layer (composed
of oxides and/or the intermetallic phases) to act as a barrier
to carbon diffusion may be responsible for an observed increase
in interfacial TiC formation leading to practical diamond
growth rates of about 1 µm/hour.
[Back to top]
Chemical-Solution Deposition of Hafnia Films on Self-Assembled
Molecular Monolayers
Michael Z. Hu, Amy C. DeBaillie, Yayi Wei and Gerold E.
Jellison
Hafnia and zirconia films have been synthesized via
solution deposition on sulfonate-terminated molecular self-assembled
monolayers (SAMs) that are covalently anchored on surfaces
of silicon wafers. As-prepared inorganic films, consisting
of packed nanoparticles, were formed by heat-induced hydrolysis
and condensation in acidic aqueous solutions of hafnium inorganic
salt. The effects of several key synthesis process parameters—such
as temperature, concentration of the hafnium salt, and acidity
(i.e., concentration of added hydrochloric acid)—on
the thickness, growth kinetics, and surface features of the
films were studied through characterization by ellipsometry,
atomic force microscopy, and transmission electron microscopy.
In addition, solid particle precipitation in the bulk solutions
was investigated with real-time dynamic light scattering and
small-angle X-ray scattering techniques (for solid particle
nucleation and growth kinetics) as well as with scanning electron
microscopy (for visualizing solid size and morphology). The
formation of hafnia films occurs right after the induction
period, which is the time corresponding to the turbidity appearance
due to solid particle formation in the bulk solutions. The
initial growth rate of the film increases with increasing
temperature and hafnium salt concentration and decreasing
hydrochloric acid concentration. Our results suggest that
the heterogeneous nucleation and growth mechanism might be
responsible for the formation of the first layer of hafnia
on the SAM surface. However, under the conditions tested,
hafnia films seem to grow thicker mainly by a “cluster
growth” mechanism due to adherence of nanoparticles
from the bulk solutions. Although decreasing in the rate of
nucleation and growth, nanoclusters or nanoparticles (continuously
formed after the induction period) can still contribute to
film deposition. The effects of process parameters on the
film growth rate are consistent with the trend of their effects
on particle growth rate in the bulk solutions. Tests of multiple
batch deposition on the same surface, suggesting a liquid-flow
deposition scheme, show a potential to improve film growth
kinetics and to reduce film surface roughness. In comparison
with zirconia systems, the hydrolysis and film growth rate
for hafnia systems are slower; however, the film characteristics
of hafnia are quite similar to those of zirconia.
[Back to top]
Electron Transfer and Nano-Scale Motions in Nitrogenase
Fe-Protein
Mi Suk Jeong and Se Bok Jang
During biological nitrogen fixation, the nitrogenase Fe-protein
containing the [4Fe-4S] metal cluster has been shown to function
in electron transfer to the MoFe-protein. This function of
the Fe-protein is dependent on its conformational state and
the metal cluster of the active site. This review will summarize
the structures of the nucleotide bound (or “off”)
and amino-acid-substituted Fe-protein as well as the properties
of the metal cluster in Fe-protein. The conformational changes
in the nucleotide-dependent switch regions increase the driving
force, leading to intermolecular electron transfer and macromolecular
complex formation from the [4Fe-4S] metal cluster of the Fe-protein
to the substrate reduction site of the MoFe-protein.
[Back to top]
Nanomagnets-From Fundamental Physics to Biomedicine
Pedro Tartaj
Nanomagnets are expected to expand the capabilities of widely
established technologies such as data recording and to implement
new functionalities of applicability in biosciences. The basis
for these potential benefits of nanomagnets is their intrinsic
small size and their outstanding properties derived from finite-size
and surface effects as well as collective phenomena and unusual
transport properties. This review aims to describe recent
developments on the potential use of nanomagnets in data recording,
which rest in three fundamental approaches and their combinations
(composition, shape and exchange interactions). Aside from
data recording, we also describe recent advances on the use
of nanomagnets in biosciences from analytical (biosensors,
magnetic resonance imaging, separation) to therapeutic applications
(drug delivery, hyperthermia eradication of malignancy). Special
emphasis has been set in understanding the physics behind
the benefits of using nanomagnets of different characteristics.
Finally, we have addressed some of the perspectives and challenges
for the potential future development of nanomagnets and applications
based on these systems.
[Back to top]
Liposomes as Vehicles for Enhancing Drug Delivery
Via Skin Routes
Jia-You Fang, Tsong-Long Hwang and Yen-Ling Huang
The delivery of drugs via skin routes has been
extensively investigated. Nevertheless, clinical applications
are limited by the stratum corneum (SC), the predominant barrier
of the skin. One of the possibilities for increasing skin
absorption or permeation of drugs is the use of nano/submicron
vesicular systems. Classic liposomes are of little value as
carriers for drug delivery via the skin because they
do not deeply penetrate it. Only specially designed liposomes
have been shown to be capable of achieving enhanced delivery.
Liposomes are tiny spheres ranging in diameter from 50 nm
to several microns. This review article explores the types
and mechanisms involved with liposomes with nanostructures
for enhancing topical or transdermal drug delivery. The incorporation
of some additives such as anionic surfactants and ethanol
can fluidize the phospholipid bilayers, thus increasing the
depths to which liposomes can penetrate into the intercellular
pathways of the skin. Hair follicles are also important for
the enhancement of transdermal liposomes. Niosomes, non-ionic
surfactant vesicles, are alternatives to liposomes, which
are also discussed in this review. Physical methods such as
iontophoresis, ultrasound, and tape-stripping can further
assist the delivery of drugs encapsulated in liposomes. Recent
breakthroughs with liposomes are beneficial to topically applied
permeants, especially for dermatological medications, cosmetic
ingredients, and protein/peptide macromolecules.
[Back to top]
One Dimensional Nanomaterials: Preparation, Structures,
and Assembly
Yingjun Liu, Zuwei Ma and Seeram Ramakrishna
Due to the remarkable specific physical and chemical properties
as well as the potential application, one-dimensional (1D)
nanomaterials, such as nanowires, nanofibers, nanobelts, nanorods,
etc., have attracted great research interests. This paper
explores the fabrication strategies that enable rational design
and predictable production of 1D nanomaterials, such as crystallization
and electrospinning, discusses several methods for generating
heterostructured 1D nanomaterials, and ends by evaluation
of several large quantity and high quality bottom-up techniques
for building up nanostructures using 1D nanomaterials, both
ex situ assembly and in situ growth.
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