Scientists at Yale University have developed a novel cancer immunotherapy that rapidly grows and enhances a patient’s immune cells outside the body using carbon nanotube-polymer composites. The immune cells can then be injected back into a patient’s blood to boost the immune response or fight cancer.

“In repressing the body’s immune response, tumors are like a castle with a moat around it,” said Tarek Fahmy, Yale Cancer Center member, associate professor of biomedical engineering and the study’s principal investigator. “Our method recruits significantly more cells to the battle and arms them to become superkillers.”

The researchers used bundled carbon nanotubes (CNTs) to incubate cytotoxic T cells, a type of white blood cell that is key to immune system functions and fighting cancer. According to the researchers, the topography of the CNTs enhances interactions between cells and long-term cultures, providing a fast and effective stimulation of the cytotoxic T cells. The researchers modified the CNTs by chemically binding them to polymer nanoparticles that held Interleukin-2, a cell signaling protein that encourages T cell growth and proliferation. Additionally, in order to mimic the body’s methods for stimulating cytotoxic T cell proliferation, the scientists seeded the surfaces of the CNTs with molecules that signaled which of the patient’s cells were foreign or toxic and should be attacked.

According to Fahmy, previous procedures for boosting antigen-specific T cells required exposing the patient’s harvested immune cells to other cells that stimulate activation and proliferation, a costly procedure that risks an adverse reaction to foreign cells. The Yale team’s use of magnetic CNT-polymer composites eliminates that risk by using simple, inexpensive magnets.

Over the span of 14 days, the number of T cells cultured on the composite nanosystem expanded by a factor of 200. Also, the method required 1,000 times less Interleukin-2 than conventional culture conditions. A magnet was used to separate the CNT-polymer composites from the T cells prior to injection.