WillWare writes "Last November there was a press release (16 November 2001) about a potential cancer treatment agent called a nanogenerator, under development at the Memorial Sloan-Kettering Cancer Center, with subsequent discussion here at Nanodot. The treatment involves a monoclonal antibody connected to a radioactive actinium atom. The antibody somehow targets cancer cells selectively, so that the decaying actinium is brought into the cell. The actinium releases four alpha particles as it decays, which are energetic enough to usually kill the cell. The timing of these particles follows a Poisson distribution over time, so the material must be prepared and transported on a careful schedule.
It would be nice if the actinium atom could be replaced by something that could be activated from an energy source external to the patient's body. This would allow for long-term storage, rather than needing to process the stuff soon before treatment. The absorption spectrum for water alternates several times between transparent and opaque, so it should be possible to get energy to the "weapon" using EM radiation that has minimal effect on surrounding tissue.
One strategy could be to use a benign molecule that breaks into toxic pieces when stimulated. This would be a one-time use weapon. This would leave the question of ensuring that the toxic products would not do further damage after the cancer cell was killed.
If the weapon could be fired repeatedly, it would overcome the limitation that actinium releases only four alpha particles. The function of the weapon itself could be merely to transduce received EM energy to a frequency that is absorbed by water, thereby heating and hopefully killing the cancer cell. It may be possible to find such a transducer simply by searching databases of known molecules and their absorption spectra."