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Because of their small size, nanoparticles are prime candidates for delivering drugs to specific areas.
Nanoparticles can penetrate the blood brain barrier and skin epithilial junctions as well as some of the body's other natural defenses which normal drug delivery systems cannot breach.
One of the most researched nanoparticles in developing drug delivery systems has been varieties of the fullerene family(C60 and C80).
A problem with the buckyballs, which are composed entirely of carbon, is that they are not soluble in water.
The carbon nanostructure must be modified or functionalized by attaching water soluble molecules to the outside of the sphere.
So, even though a normal buckyball is like a grain of sand, a functionalized buckyball can be dissolved.
Researchers at Rice University (a conjunction of the Department of Chemistry, Smalley Institute for Nanoscale Sciene, and the Center for Biological and Environmental Nanotechnology) and the University of Texas M.D. Anderson Cancer Center have functionalized water-soluble C60 buckyballs with anti-tumor drugs.
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Water-soluble C60 derivatives
Image from Chemical Communications, 2006, 3004 - 3006
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The gp240 antigen is present on more than 80% of melanoma cells, so by attaching the soluble buckyball to gp240's corresponding antibody, buckyballs can congregate at the site of a tumor.
gp240's antibody is ZME-018 and the Anderson Cancer Center research group has shown that anti-cancer drugs can be delivered to a cancer site through ZME-018's natural attraction to gp240.
The advantage of using buckyballs over directly attaching cancer drugs with ZME-018 is that more varieties of drugs can be delivered to a tumor.
Normal avenues of delivery prevent the amount of drug delivered to the desired site at one time.
When attaching drugs to an antibody, only a few molecules can be attached at one time.
As more molecules are added, though, the delivery of the drugs become less precise.
Researchers at Rice have attached over 40 buckyballs to a single antibody; therefore, many different treatments may be prepared for each buckykball.
Another advantage of the buckyball system is that when dissolved in biofluids, they tend to form clusters.
The clusters cause the drugs to stay at the tumor site longer for prolonged exposure to treatment.
Sources:
Chemical Communications, 2006, 3004-3006 | Fullerene (C60) immunoconjugates: interaction of water-soluble C60 derivatives with the murine anti-gp240 melanoma antibody
Buckyball-Antibody Combination Delivers Antitumor Drugs | NCI Alliance for Nanotechnology in Cancer July 2006
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