Biomedical Engineering Reference
In-Depth Information
In this study, delivery was targeted to a single lesion in a specific hepatic
segment, using a small, externally positioned magnet (5 kilogauss) to create a
localized magnetic field within the body over the tumor site. The physical force
created by the magnetic field induces transport (extravasation) of the MTCs through
the vascular wall. The external magnet remains in place for about 15 min after
dosing. Upon removal of the magnet, the MTCs do not recirculate but are retained
in the tissue, where the drug then desorbs from the MTCs, leading to sustained
release of the particles at the desired site.
7.3 Drug-Infused Nanoparticles Stop Cancer from Spreading
By using tumor-targeting nanoparticles filled with chemotherapy drugs, scientists
kept kidney and pancreas cancers from spreading through the bodies of mice
(Fig.
33
). Researchers led by University of California, San Diego pathologist
David Cheresh designed nanoparticles that selectively attached to a protein found
on the surface of blood vessels that supply tumors with nutrients and oxygen [
109
].
The particles were loaded with doxorubicin, an effective but highly toxic anticancer
drug with side effects ranging from white cell destruction to fatal heart disease. By
targeting blood vessel cells, the researchers needed just one-fifteenth of the amount
used in a traditional, system-flooding dose.
Duke University bioengineers have developed a simple and inexpensive method
for loading cancer drug payloads into nanoscale delivery vehicles, and have
demonstrated in animal models that this new nanoformulation can eliminate tumors
after a single treatment [
109
]. After delivering the drug to the tumor, the delivery
Fig. 33 Prevention of spread of cancer to other body parts (Adapted from [
109
])
