"This is an exciting opportunity to apply novel materials such as fullerenes to generate targeted therapeutics with unique properties," Rosenblum said. "If successful, this could usher in a new class of agents for therapy not only for cancer, but for other diseases as well."
While it's possible to attach drug molecules directly to antibodies, Wilson said scientists haven't been able to attach more than a handful of drug molecules to an antibody without significantly changing its targeting ability. That happens, in large part, because the chemical bonds that are used to attach the drugs -- strong, covalent bonds -- tend to block the targeting centers on the antibody's surface. If an antibody is modified with too many covalent bonds, the chemical changes will destroy its ability to recognize the cancer it was intended to attack.
Wilson said the team from Rice and M. D. Anderson had planned to overcome this limitation by attaching multiple molecules of Taxol to each buckyball, which would then be covalently connected to the antibodies. To the team's surprise, many more buckyballs than expected attached themselves to the antibody. Moreover, no covalent bonds were required, so the increased payload did not significantly change the targeting ability of the antibody.
Wilson said certain binding sites on the antibody are hydrophobic (water repelling), and the team believes that these hydrophobic sites attract the hydrophobic buckyballs in large numbers so multiple drugs can be loaded into a single antibody in a spontaneous manner to give the antibody-drug agent more "bang for the buck."
"The use of these nanomaterials solves some intractable problems in targeted therapy and additionally demonstrates the increasing value of the team science approach bridging different disciplines to uniquely address existing problems," Rosenblum said.