| Current
Nanoscience
ISSN: 1573-4137
Current Nanoscience
Volume 1, Number 3, November 2005
Contents
Nanomedicine Pp.177
Dwaine F. Emerich and Christopher G. Thanos
[Abstract]
Place of Nanofiltration for Assuring Viral Safety
of Biologicals Pp.189
T. Burnouf, M. Radosevich, H.A. Goubran and H. Willkommen
[Abstract]
Drug Delivery Across the Blood-Brain Barrier Pp.203
Anika M.S. Hartz, Björn Bauer, Carsten H. Baehr,
David S. Miller and Gert Fricker
[Abstract]
Nanofocusing Devices Development and Nano-Medicine
Pp.211
Ivan D. Nikolov
[Abstract]
Small Neuroscience: The Nanostructure of the Central
Nervous System and Emerging Nanotechnology Applications Pp.225
Gabriel A. Silva
[Abstract]
Nanoparticle Formulation Increases Oral Bioavailability
of Poorly Soluble Drugs: Approaches, Experimental Evidences
and Theory Pp.237
Lee Jia
[Abstract]
Nano-Patterning in Polymeric Materials and Biological
Objects Using Atomic Force Microscopy Electrostatic Nanolithography
Pp.245
Sergei F. Lyuksyutov
[Abstract]
Fullerene-like Nanoparticles of Titanium Disulfide
Pp.253
Alexander Margolin, Ronit Popovitz-Biro, Ana Albu-Yaron,Alexander
Moshkovich, Lev Rapoport and Reshef Tenne
[Abstract]
Global Governmental Investment in Nanotechnologies
Pp.263
Lee Jia
[Abstract]
Abstracts
[Back to top]
Nanomedicine
Dwaine F. Emerich and Christopher G. Thanos
Nanotechnology is a multidisciplinary scientific field with
roots in medicine, communications, genomics, and robotics.
Miniaturization provides cost effective and more rapidly functioning
mechanical, chemical and biological components. But nanometer
sized objects also possess self-ordering and assembly behaviors
quite different from larger macro objects that when understood
and harnessed will dramatically enhance the quality of human
life. The potential applications of nanotechnology encompass
virtually every aspect of our lives but one of the greatest
values of nanotechnology will be the development of new and
effective medical treatments (i.e. nanomedicine). This review
focuses on the potential of nanomedicine including using nanoparticles
for diagnostic and screening purposes, viral detection, developing
artificial receptors, DNA sequencing using nanopores, manufacture
of unique drug delivery systems, gene therapy applications,
and the enablement of tissue engineering.
[Back to top]
Place of Nanofiltration for Assuring Viral Safety
of Biologicals
T. Burnouf, M. Radosevich, H.A. Goubran and H. Willkommen
Viruses are nanometer size organisms (range from 18 to 250
nm) that can potentially contaminate the feedstocks from animal
or human origins used to manufacture biopharmaceutical products.
Various measures are taken to ensure the optimal viral safety
of this class of products. Selection and screening of starting
materials play an important role in safeguarding from the
introduction of viruses into the downstream processing but
they have limits in specificity and sensitivity. Purification
methods of protein biopharmaceutical products may also contribute
to viral reduction, but since viruses exhibit a wide range
of biochemical characteristics and resistance to physico-chemical
treatments, complete elimination of infectious agents is not
guaranteed. Therefore, the viral safety of animal derived
biopharmaceutical products is well recognized to rely largely
upon the use of deliberately introduced and validated viral
inactivation and/or removal steps. A major progress in viral
safety has been made recently by the development and availability
of biocompatible viral filtration (also known as nanofiltration)
systems using membranes of a pore size as small as 15 nm;
these systems are specifically designed to allow, depending
upon membrane used, typically over 4 to 6 logs of virus removal
under conditions ensuring good protein permeability and recovery.
Validation studies and production experience throughout the
world have demonstrated that viral nanofiltration is a robust
and reliable viral reduction technique that can be applied
to essentially all biological products. This review analyzes
the virus risks of biopharmaceutical products (human plasma
derivatives, horse and sheep plasma-derived products, recombinant
proteins and monoclonal antibodies), the various viral inactivation
methods used at present, and the increasing role that viral
nanofiltration is playing in assuring the safety of biopharmaceutical
products.
[Back to top]
Drug Delivery Across the Blood-Brain Barrier
Anika M.S. Hartz, Björn Bauer, Carsten H. Baehr,
David S. Miller and Gert Fricker
The blood brain barrier, formed by brain capillary endothelial
cells, represents the major obstacle for drug entry into the
central nervous system. Efforts are ongoing to overcome this
barrier without causing permanent damage to brain tissue.
The present review attempts to provide key information on
cerebral microvessel anatomy, features contributing to barrier
function and current approaches in overcoming the blood-brain
barrier using cellular and molecular methodologies to transfer
drugs to the brain as well as intelligent drug delivery systems.
[Back to top]
Nanofocusing Devices Development and Nano-Medicine
Ivan D. Nikolov
Optical nano-phenomena are defined in the field of nanotechnology
for nano-metric architectures and nano-structural devices.
A short mini-review of the latest books is presented. The
definitions of nano-photonics and nanofocusing are determined.
An integrated optical scheme of the obtained near-field nanofocusing
probe is discussed. Optical aspects of the nanofocusing recording
probes are examined. Aberration conditions of the optical
head intended for a higher-density disk memory are considered.
The residual and technological aberrations are presented.
The obtained optical configurations are shown using ray-trace
modeling and wave-optics analysis. The nanofocused spot is
computed as 25 nm for a vertical cavity surface emitting laser
(VCSEL) beam of 8 µm and the far-field diffraction limit
is calculated as 150 nm for a microlens diameter of 13 µm.
The nanofocused spots from 20 nm at the geometrical limit
and up to 130 nm at the diffraction size have been obtained
using two-layer anti-reflection coating on both surfaces of
the fabricated microlens structure. The optically integrated
arrayed nanofocusing device is presented. The optical power
density is compressed more than 1000 times to the exact nanofocused
spot in comparison with the energy of the input VCSEL micro-beam.
Nano-optical, bio-optical and nano-medicinal devices are underlined.
[Back to top]
Small Neuroscience: The Nanostructure of the Central
Nervous System and Emerging Nanotechnology Applications
Gabriel A. Silva
The design and application of bionanotechnologies aimed
at the central nervous system (CNS) provide powerful new approaches
for studying cell and molecular biology and physiology. Emerging
clinically oriented bionanotechnologies are targeting CNS
pathologies such as trauma or degenerative events. The successful
and meaningful development of bionanotechnologies designed
to interact with the CNS as research or clinical tools require
an understanding of the relevant neurophysiology and neuropathology,
an appreciation of the inherent ‘nanoscale’ structure
of the CNS, and an understanding of the relevant chemistry
and materials science and engineering. This review gives an
introduction to the structure and organization of the CNS
starting at the organ level and working down in spatial scale
to the cellular and molecular levels, with specific examples
of biological ‘nanoengineering’ in neural cells.
This is followed by a discussion of some of the unique challenges
and obstacles associated with developing bionanotechnologies
aimed at the CNS, and a discussion of emerging nanotechnologies
for neuroscience applications.
[Back to top]
Nanoparticle Formulation Increases Oral Bioavailability
of Poorly Soluble Drugs: Approaches, Experimental Evidences
and Theory
Lee Jia
The increasing frequency at which poorly soluble new chemical
entities are being discovered raises concerns in the pharmaceutical
industry about drugability associated with erratic dissolution
and low bioavailability of these hydrophobic compounds. Nanonization
provides a plausible pharmaceutical basis for enhancing oral
bioavailability and therapeutic effectiveness of these compounds
by increasing their surface area. This paper surveys methods
available to pharmaceutical manufacturing nanoparticles, including
wet chemical processes, media milling, high pressure homogenization,
gas-phase synthesis, and form-in-place processes, and elaborates
physicochemical rational and gastrointestinal physiological
basis upon which nano-drugs can be readily absorbed. Relevant
examples are illustrated to show that nano-drugs permeate
Caco-2 cell monolayer fast and are well absorbed into animal
systemic circulation with high Tmax and AUC, resulting in
oral bioavailability higher than their counterpart micro-drugs.
The size-dependent permeability and bioavailability should
be given particular consideration in the development of potent
and selective drug candidates with poor aqueous solubility.
[Back to top]
Nano-Patterning in Polymeric Materials and Biological
Objects Using Atomic Force Microscopy Electrostatic Nanolithography
Sergei F. Lyuksyutov
In this article we are concerned with several aspects related
to atomic force microscopy electrostatic nanolithography (AFMEN).
AFMEN technique is based on manipulation of nano-amounts of
dielectric materials in strong 108-1010
Vm-1 electric field. In polymer films of different
physical-chemical properties AFMEN produces erasable nano-structures
that are 10–300 nm in diameter and 0.5–20 nm in
height through Joule heating of polymeric molecules between
conductive AFM tip and substrate followed by electrostatic
attraction of the softened polymer towards the tip. We discuss
AFMEN for potential data storage applications in polymeric
materials. Additionally, it is demonstrated that AFMEN manipulates
bundles of Wiseana Iridovirus and produces noticeable
changes in capsids composing individual virions.
[Back to top]
Fullerene-like Nanoparticles of Titanium Disulfide
Alexander Margolin, Ronit Popovitz-Biro, Ana Albu-Yaron,
Alexander Moshkovich, Lev Rapoport and Reshef Tenne
TiS2 nanoparticles with nested fullerene-like
structure (IF) 60-120 nm in size consisting of up to 100 concentric
molecular layers and having quite a perfectly spherical shape
were obtained by reacting TiCl4 and H2S
using first a horizontal and subsequently a vertical reactor.
The proposed growth mechanism of these nanoparticles, i.e.
nucleation and growth, is radically different from the one
proposed for the growth of the fullerene-like WS2 from
the respective oxide nanoparticles. It was found that adding
1-2% IF-TiS2 improves the behavior of
lubricating oil substantially. The improved performance of
the additive was attributed to the nearly spherical shape
of the nanoparticles which promotes rolling friction.
[Back to top]
Global Governmental Investment in Nanotechnologies
Lee Jia
Nanotechnologies seem to have huge potential to bring benefits
in areas as diverse as drug development, water decontamination,
information and communication infrastructures, and the production
of stronger, lighter and perfect nanomaterials. This potential
attracts global investment from governments and private sectors
in nanotechnologies with the hopes that R&D and commercial
applications of nanomaterials, nanodevices, nanoparticles
and nanodrugs will provide new impetus, after the ebb-tides
of biotechnology and dotcom, to turn faltering economies around.
The global governmental funding has been actively promoting
industrial and academic cooperation to realize big prosperity
from the nanotechnologies. This article summarizes historic
trends and status of global governmental supports for nanotechnologies.
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