Biomedical Engineering Reference
In-Depth Information
nanoscale dimensions that are suitable for intracellular measurements. The use
of such nanosensors for monitoring in vivo biological processes in single living
cells could greatly improve current knowledge of cellular functions. Biosen-
sors with optical transduction can involve fiber optics for chemical sensors and
biosensors.
112-114
One of the most active areas of research for NM applications is in medi-
cine. Nanosized liposomes have been used to encapsulate anticancer drugs for
the treatment of various diseases.
115-134
A number of studies using magnetic
NPs in the analyses of blood, urine, and other body fluids to speed up sepa-
ration and improve selectivity are ongoing.
15,16,23-26,32,33,36,51,52,59,108,109,135-153
Several scientists at academic and industrial institutions have developed
engineered fluorescent NMs that form the basis for new detection technolo-
gies.
9,25,33,35,49,66,68,78,100,135,154-173
These biocompatible NMs are used in new
devices and systems for infectious and genetic disease diagnosis, treatment, and
for drug discovery.
15-17,139,174
Recent studies show that NMs can be effective in
delivering a variety of vaccine antigens/epitopes with enhancements of antibody
and/or cellular responses.
30,108,109,135,154,175-177,178
Chitosan, in particular, is a
novel nasal delivery system for vaccines and inorganic particles
38,179
with sizes
varying from 40 nm to <1 µm. Parenteral injection routes (SC/IM/IP) with NM-
based vaccines showed efficacy in the range of 40-800 nm NMs.
180-182
A well-
recognized obstacle with the use of NMs in biomolecule delivery is that they
are too rapidly cleared from the body.
30,123,183-185
However, NMs larger than 10
nm will avoid single pass renal clearance and the presence of negative charge
minimizes nonspecific interaction with proteins and cells to achieve pharmaco-
kinetic (PK) manipulations.
30
These NMs can be highly effective when readily
taken up by antigen-presenting cells.
It has been shown that the remarkable recognition capabilities of biomol-
ecules when combined with the unique properties of NMs can lead to novel
tissue substitutes, biological electronics such as biosensors, sensitive diagnos-
tic systems, and controlled drug delivery systems with significantly improved
performances. In this light, NMs can be divided into three major categories
according to their geometry, such as equiaxed, one-dimensional (or fibrous),
and two-dimensional (or lamellar) forms. Selected examples and typical appli-
cations of such NMs and their use in biomedical applications are highlighted in
Table 1.1
.
Many nano-enabled medical products have entered the market to date and
as the applications grow and infiltrate complicated diseases such as all kinds
of cancer, cardiac, and neurodegenerative disorders, infection, tissue engi-
neering, etc., the market is predicted to reach considerable growth in the near
future.
1
This has been shown in the application of NMs in biomedical sciences
that posted a year-on-year growth of over 37% in 2009.
1
In 2013, this area is
expected to close at US$750 M with a CAGR of over 30% since 2010. The US
leads the nanotechnology market and accounts for an estimated share of around
35% of the global nanotechnology market.
1
