Biomedical Engineering Reference
In-Depth Information
stem cell dif erentiation and transplantation [190]. Nanopharmaceuticals
have a number of advancements with a focus on engineering novel applica-
tions. Nanotechnology also of ers the ability to detect diseases at much ear-
lier stages, such as i nding hidden or overt metastatic colonies ot en seen in
patients diagnosed with breast, lung, colon, prostate, and ovarian cancer.
Diagnostic applications could build upon conventional procedures using
nanoparticles, such as colloidal gold, iron oxide crystals, and quantum dots.
Additionally, diseases may be managed by multifunctional agents encom-
passing both imaging and therapeutic capabilities, thus allowing simulta-
neous monitoring and treatment [191].
Quantum dots (QDs) are semiconductor nanocrystals that emit l uo-
rescence on excitation with a light source. h ey have excellent optical
properties, including high brightness, resistance to photobleaching and
tunable wavelength. h e surface modii cation of QDs enables their poten-
tial application in cancer imaging. Quantum dots with near-infrared emis-
sion could be applied to sentinel lymph-node mapping to aid biopsy and
surgery. Conjugation of QDs with biomolecules, including peptides and
antibodies, could be used to target tumors
in vivo
. h e use of QDs for can-
cer diagnosis and treatment is very crucial from a clinical standpoint [192].
h e enhanced diagnostic and therapeutic medicine for use against cancer
and other diseases is possible due to nanomedicine. h e special properties
exihibited by nanoscale-size quantum dots, metal colloids, superparamag-
netic iron oxide, and carbon-based nanostructures give rise to their nano-
technologic behavior, i.e., theranostics (both diagnostic and therapeutic by
design) [193]. Biomedical imaging depends on the development of probes
that combine low toxicity with high sensitivity, resolution, and stability.
Fluorescent core-shell silica nanoparticles with narrow size distributions
and enhanced photostability (C dots), provide appealing
in-vivo
applica-
tions in cancer biology. Within the emerging i eld of nanomedicine, C dots,
which are nontoxic at biologically relevant concentrations, are used in a
broad range of imaging applications including intravital visualization of
capillaries and macrophages, sentinel lymph node mapping, and peptide-
mediated multicolor cell labeling for real-time imaging of tumor metasta-
sis and tracking of injected bone marrow cells in mice [194]. Man-made
nanostructured materials such as fullerenes, nanoparticles, nanopowders,
nanotubes, nanowires, nanorods, nanoi bers, quantum dots, dendrimers,
nanoclusters, nanocrystals, and nanocomposites are widely produced in
large quantities due to their wide potential applications, including skin-
care, consumer products, healthcare, electronics, photonics, biotechnol-
ogy, engineering products, pharmaceuticals, drug delivery, and agriculture.
However, human exposure to these nanomaterials enter the body through
