systems has driven nanomaterials more tow ard life science. Moreover , this
nanotech nology ca n be applicable to the detection of a wide var iety of bacterial
pathogens that can be used as bioterror agents in food, clinical samples, and
environmental samples [28]. For example, a recent report has introduced the
quantum dot-based rapid imm unoas says for the detect ion of Listeria
monocytogenes that is an important food-bor ne pathogen with an extr emely
high mortality rate [29]. In addition, Feline calicivirus (FCV) has been detected
by using monoclonal antibody-conjugated gold nanoparticles, which prod uce
Raman signatures as a recognition tool [30]. Together, development of
nanotech nology will be a ble to open the new era of biosensors for rapid and
ultrasensitive determination of pathogenic microorganism.
Nanobiotechnology, which is related to the biomedical application of
nanomaterials or nanostructures, is one of the rapidly growing branchs within
nanotechnology. With the development of this technology, important advances
in the detection, diagnosis, and treatment of cancers are under progress.
Moreover, nan oparticles are being actively developed for tumor targeting as
well as tumor imaging in vivo, development of biomarkers, and targeted drug
or gene delivery [31]. Thus, the nano-based techniques can be applied
ubiquitously in the management of different malignant diseases. That is to
say, the use of nanoparticles may provide the selective detection of critical
tumor marker proteins for monitoring as well as efficient treatment options. In
fact, nanotechnology-based approaches are being actively investigated in
cancer imaging [32, 33]. For example, oligonucleotide-functionalized gold
nanoparticles have been utilized for the multiplex detection of cancer
biomarkers such as prostate specific antigen (PSA), human chorionic
gonadotropin (HCG, testicular cancer marker), and a-fetoprotein (AFP,
hepatocellular carcino ma marker) wi th high sensitivity and specificity [34].
Semiconductor quantum dots have been applied to detect the cancer
biomarkers in blood and cancer biopsy samples with the aid of fluor escence
[35]. Recently, active tumor targeting of nanoparticles has been achieved with
direct targeting or pretargeting methods [36]. In direct targeting, nanoparticles
are covalently coupled with the ligand of interest and the resulting drug carrier
can be administered at once. In the pretargeting method, the therapeutic
molecule is not coupled with the ligand and is administered after appropriate
delay time because this delay will allow time for the antibody to localize and
concentrate in tumor sites with the help of avidinbiotin system or specific
antibody [37, 38]. There is a great need for the development of imaging
techniques that specifically identify an giogenic blood vessels. A recent report
demonstrates that MR molecular imaging of angiogenesis has been achieved by
using a bimodal lipidic nanoparticles-labeled alphavbeta-3-inte grin [39]. Some
research groups have described another novel techni que, which uses folate-
conjugated fluorescent silica nanoshells in order to detect malignant cells that
overexpress folate receptors [40]. Nano shells are composed of a dielectric silica
core covered by a thin metal shell that is typically gold. Based on the relative
dimensions of the core radius and shell thickne ss, nanoshells can be designed to
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