Biomedical Engineering Reference
In-Depth Information
delivery systems clearance can be reduced by altering the pharmacokinetics of the
drug. Poor biodistribution is a problem that can affect normal tissues through
widespread distribution, but the particulates from drug delivery systems lower the
volume of distribution and reduce the effect on non-target tissue. Potential nano
drugs will work by very specific and well-understood mechanisms; one of the
major impacts of nanotechnology and nanoscience will be in leading development
of completely new drugs with more useful behavior and less side effects.
Diagnostic and Imaging Techniques
Carbon nanotubes and gold nanoparticles are being used in a sensor that detects
proteins indicative of oral cancer. Tests have shown this sensor to be accurate in
detecting oral cancer and provide results in less than an hour. Silver nanorods in a
diagnostic system are being used to separate viruses, bacteria, and other micro-
scopic components of blood samples, allowing clearer Raman spectroscopy signals
of the components. This method has been demonstrated to allow identification of
viruses and bacteria in less than an hour.
Iron oxide nanoparticles can be used to improve MRI images of cancer tumors.
The nanoparticle is coated with a peptide that binds to a cancer tumor; once the
nanoparticles are attached to the tumor the magnetic property of their oxide
enhances the images from the Magnetic Resonance Imagining scan. Nanoparticles
can attach to proteins or other molecules, allowing detection of disease indicators
in a lab sample at a very early stage. There are several efforts to develop nano-
particle disease detection systems underway. One system being developed by
Nanosphere, Inc. uses gold nanoparticles, nanosphere has clinical study results
with their Verigene system involving its ability to detect four different nucleic
acids, while another system being developed by T2 Biosystems uses magnetic
nanoparticles to identify specimens, including proteins, nucleic acids, and other
materials.
Gold nanoparticles that have antibodies attached can provide quick diagnosis of
flu virus. When light is directed on a sample containing virus particles and nano-
particles the amount of light reflected back increases because the nanoparticles
cluster around virus particles, allowing a much faster test than those currently used.
Quantum Dots (qdots) may be used in the future for locating cancer tumors in
patients and in the near term for performing diagnostic tests in samples. Invitro-
gen's website provides information about qdots that are available for both uses,
although at this time the use ''in vivo'' is limited to experiments with lab animals.
Concerns about the toxicity of the material that qdots are made from are one of the
reasons for restricting the use of qdots in human patients. However, work is being
done with qdots composed of silicon, which is believed to be less toxic than the
cadmium contained in many qdots.
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