Antibody targets nanotubes to tumors

Researchers at Memorial Sloan-Kettering Cancer Center have created biocompatible single-walled carbon nanotubes that can target lymphomas and deliver both imaging and therapeutic molecules to these tumors.

Reporting its work in the Journal of Nuclear Medicine, the research team describes the methods it used to create these targeted, multifunctional nanotubes and its initial in vitro and in vivo test results. David Scheinberg, M.D., Ph.D., led the team of investigators.

Starting with water-soluble carbon nanotubes, which recent work has shown are nontoxic to human cells, Scheinberg's group created a construct that included a tumor-targeting antibody, a fluorescent imaging probe, and a radioactive therapeutic agent. Each nanotube, which contained approximately six antibody molecules and 114 radioactive atoms, proved to be stable in human plasma for at least 96 hours and was able to bind to targeted tumor cells. Most importantly, according to the researchers, the chemical linkages binding the radioactive element indium-111 was completely stable in human plasma for the entire 4-day experiment.

Tests using a mouse model of human lymphoma showed that this nanotube construct successfully targeted tumors while avoiding healthy cells. The researchers note that the antibody alone, that is, one not attached to a carbon nanotube, bound better to tumor cells than did the nanotube construct; they believe this difference is a result of not yet optimizing the methods they used to attach the antibodies to the carbon nanotubes.

This work, which was supported by the National Cancer Institute, is detailed in the paper "Tumor targeting with antibody-functionalized, radiolabeled carbon nanotubes." An investigator from Cornell University also participated in this study. An abstract of this paper is available through PubMed. View abstract.