Researchers have now developed drug-loaded nanoparticles that can be administered directly at the brain tumor site, killing the cancer cells.
The new technique, developed by researchers at Yale and Johns Hopkins, can save lives of some 15,000 people in the U.S. diagnosed with a deadly type of brain tumor called Glioblastoma multiforme.
People with Glioblastoma multiforme rarely live for about a year after therapy that includes chemotherapy plus surgery and five year survival post-treatment is low- about 10 percent. The cancer is categorized as a Grade IV (most serious) astrocytoma. It originates from a line of astrocytes that are star-shaped cells supporting nerve cells.
Currently, treatments include administering drugs either orally or intravenously. One of the major drawbacks for this treatment is the blood-brain barrier that prevents drugs from reaching the site. Also, implants that get the drugs directly to the cancer cells don't reach migrating cancer cells. These migrating cells can avoid the drugs and regrow under normal conditions.
The new drug delivery system sends drugs directly at the site, increasing the rate at which cancer cells are killed.
"We wanted to make a system that would penetrate into the brain and deliver drugs to a greater volume of tissue. Drugs have to get to tumor cells in order to work, and they have to be the right drugs," said Mark Saltzman, a biomedical engineer at Yale and principal investigator of the research, according to a news release.
The new drug delivery system targets drugs at the cancer site and lets the drug stay in the site for long. The system also reduces risk of side-effects of drugs, according to Dr. Joseph M. Piepmeier, a member of the research team.
The drugs carrying nanoparticles are just 70 nanometers in diameter and are administered using a catheter. The particles are small enough to move freely and release the drugs gradually.
The system was tested on rats where DI-loaded nanoparticles extended median survival to 280 days, researchers said. Rats that had got other treatment had survived for 180 days while those without any treatment lived for 147 days.
Researchers said that the system of combining nanoparticles with other drugs that target cancers can be developed.
The study, "Highly penetrative, drug-loaded nanocarriers improve treatment of glioblastoma," is published in the Proceedings of the National Academy of Sciences.