Radiotherapy with targeted nanogenerators

The use of a safe, efficient, highly specific carrier capable of delivering radioactivity precisely with in a tumor is a long sought after goal in the treatment of cancer. In November 16 Science Michael McDevitt and colleagues from Memorial Sloan-Kettering Cancer Center, New York describe a new efficient method to target molecular-sized generators of alpha-emitting isotopes to the inside of cancer cells.

McDevitt et al. constructed a nanogenerator of alpha-emitting particles from a single atom of actinium-225 coupled to an internalizing monoclonal antibody. They found that injection of single doses of the constructs at kilobecquerel (nanocurie) levels into mice bearing solid prostate carcinoma or disseminated human lymphoma induced tumor regression and prolonged survival, without toxicity, in a substantial fraction of animals (Science 2001, 294:1537-1540).

"Because of the extraordinary potency of 225Ac generators, little radioactivity would be required for therapeutic human use, allowing for economical out-patient use and safety" concluded the ...