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Researchers at the University of California, San Diego have developed a novel method of disguising nanoparticles as red blood cells, enabling them to evade the body's immune system and deliver cancer-fighting drugs straight to a tumor. The research will be published June 27, 2011 in the online Early Edition of the Proceedings of the National Academy of Sciences.
According to the researchers, the method involves collecting the membrane from a red blood cell and wrapping it like a powerful camouflaging cloak around a biodegradable polymer nanoparticle stuffed with a cocktail of small molecule drugs. Researchers call the technique “drug-polymer blending”. Nanoparticles are less than 100 nanometers in size, about the same size as a virus. The technique allows researchers to precisely control the ratio of drugs loaded into the particle. They can also control the rate at which each drug will be released once it enters a tumor cell.
"This is the first work that combines the natural cell membrane with a synthetic nanoparticle for drug delivery applications." said Liangfang Zhang, a nanoeningeering professor at the UC San Diego Jacobs School of Engineering and Moores UCSD Cancer Center. "This nanoparticle platform will have little risk of immune response".
Researchers have been working for years on developing drug delivery systems that mimic the body's natural behavior for more effective drug delivery. That means creating vehicles such as nanoparticles that can live and circulate in the body for extended periods without being attacked by the immune system. Red blood cells live in the body for up to 180 days and, as such, are "nature's long-circulation delivery vehicle," said Zhang's student Che-Ming Hu, a UCSD PhD candidate in bioengineering, and first author on the paper.
Researchers from MIT and Brigham and Women’s Hospital already use specially designed stealth nanoparticles to deliver two very different chemo drugs, cisplatin and docetaxel, to prostate cancer cells. Other research has successfully used the technology to target liver cancer and breast cancer cells.