Researchers at the University of California, San Diego, United States, have developed a method of disguising nanoparticles as red blood cells by collecting membranes from a red blood cell and wrapping it around a biodegradeable polymer nanoparticle stuffed with a cocktail of small molecule drugs. The method will enable the nanoparticles to evade the body’s immune system and deliver cancer-fighting drugs straight to the tumor. According to Liangfang Zhang, a nanoeningeering professor, “This is the first work that combines the natural cell membrane with a synthetic nanoparticle for drug delivery applications. This nanoparticle platform will have little risk of immune response.” Current “stealth” nanoparticles can circulate in the body for hours, but Zhang’s study found that the nanoparticles coated in the membranes of red blood cells circulated in the bodies of lab mice for nearly two days. “We approached this problem from an engineering point of view and bypassed all of this fundamental biology,” said Zhang. “If the red blood cell has such a feature and we know that it has something to do with the membrane — although we don’t fully understand exactly what is going on at the protein level — we just take the whole membrane. You put the cloak on the nanoparticle, and the nanoparticle looks like a red blood cell.” Zhang said next steps include developing an approach for large-scale manufacturing of these nanoparticles for clinical use, as well as adding a targeting molecule to the membrane that will enable the particle to seek and bind to cancer cells. The team also wants to be able to put multiple drugs into the nanoparticle core, as cancer cells can develop a resistance to drugs delivered individually.
http://ucsdnews.ucsd.edu/newsrel/science/20110620CancerFightingCells.asp