Carbon Nanotubes Linked to Monoclonal Antibodies for Targeted Chemotherapy

Cancer researchers have upgraded the "magic bullet” approach to chemotherapy by combining specific anti-cancer monoclonal antibodies with carbon nanotubes that heat up when exposed to near infrared light.

The type of light is the same as is used in television remote controls or for beaming information between hand-held computers. It can penetrate human tissue to a depth of about 3.8 cm.

Investigators at the University of Texas Southwestern Medical Center (Dallas, USA; www.utsouthwestern.edu) attached carbon nanotubes to monoclonal antibodies specific for human CD22 or CD25 cancer cell membrane antigens. They reported in the June 16, 2008, online edition of the Proceedings of the [U.S] National Academy of Sciences (PNAS) that the nanotube-antibody complexes bound only to the target cancer cells, which were then killed upon exposure to near infrared light. Normal cells did not bind the antibody complexes, nor were they affected by exposure to near infrared light.

"Using near infrared light for the induction of hyperthermia is particularly attractive because living tissues do not strongly absorb radiation in this range,” said senior author Dr. Ellen Vitetta, professor of cancer immunobiology at the University of Texas Southwestern Medical Center. "Once the carbon nanotubes have bound to the tumor cells, an external source of near infrared light can be used to safely penetrate normal tissues and kill the tumor cells. Demonstrating this specific killing was the objective of this study. We have worked with targeted therapies for many years, and even when this degree of specificity can be demonstrated in a laboratory dish, there are many hurdles to translating these new therapies into clinical studies. We are just beginning to test this in mice, and although there is no guarantee it will work, we are optimistic.”


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University of Texas Southwestern Medical Center