In a paper to appear the week of April 10 in the online edition of the Proceedings of the National Academy of Sciences, the team reports a way to custom design nanoparticles so they home in on dangerous cancer cells, then enter the cells to deliver lethal doses of chemotherapy. Normal, healthy cells remain unscathed.
The team conducted experiments first on cells growing in laboratory dishes, and then on mice bearing human prostate tumors. The tumors shrank dramatically, and all of the treated mice survived the study; the untreated control animals did not.
"A single injection of our nanoparticles completely eradicated the tumors in five of the seven treated animals, and the remaining animals also had significant tumor reduction, compared to the controls," said Dr. Omid C. Farokhzad, an assistant professor at Brigham and Women's Hospital and Harvard Medical School.
Farokhzad and MIT Institute Professor Robert Langer led the team of eight researchers. (Farokhzad was formerly a research fellow in Langer's lab.)
The scientists said that further testing is needed. Although all the parts and pieces of their new system are known to be safe, the system itself must yet be proven safe and effective in humans. This means thorough testing must be done in larger animals, and eventually in humans.
"We're most interested in developing a system that ends up in the clinic helping patients," Farokhzad said. To make that happen, he added, "we brought in cancer specialists and urologists to collaborate with us."
Further, he said, from an engineering perspective "we wanted to develop a broadly applicable system, one that other investigators can alter for their own purposes."