Researchers at the University of California, San Diego, have succeeded in creating a "nanosponge" disguised as a red blood cell that can enter the body and soak up toxins caused by the likes of MRSA (methicillin-resistant Staphylococcus aureus), E. coli and animal venom while evading attack from the body's immune system.
Likewise, scientists at the La Jolla-based university can cloak a cocktail of small-molecule drugs with the membrane of a red blood cell serving as a camouflage while it targets cancer cells.
"After you discover this delivery system, you might sit back and say, 'Wow, this is so obvious,' but it wasn't so obvious before," said Liangfang Zhang, a nanoengineering professor at the UC San Diego Jacobs School of Engineering and the Moores UC San Diego Cancer Center. "Either way, it has great potential."
Zhang's research team looked at a major roadblock to fighting diseases — namely, the body's immune system — and decided to look outside the proverbial box. Rather than focusing on a solution from a biological perspective, the team implemented elements of engineering, biology and chemistry to forge a solution. About 10 scientists in all worked on the project, which recently wrapped up the research phase and is now moving towards clinical tests. Detoxifying the blood has already proven effective in mice using the nanosponge technology.
The project began about two years ago.
"We took a different approach and looked at this from an engineering standpoint," Zhang said. "If you can camouflage a nanosponge to make it look like a red blood cell, it can circulate in the body for days removing toxins. And you can use this approach to delivering cancer-fighting drugs."
This is the first time a team has combined natural cell membrane with a synthetic nanoparticle to deliver drugs, according to UC San Diego. Zhang points out that nanoparticle delivery can improve treatment and reduce the negative side effects of certain medicines.
Research is being funded in part through the National Science Foundation. Zhang said a major challenge is manufacturing the nanoparticles in large enough quantities to complete the clinical studies, along with adding a targeting molecule — a sort of honing device — that will enable the nanoparticle to find and bind to cancer cells.
While it could be up to a decade before new cancer treatments are developed through the research, nanosponges to soak up toxins could be just a few years away. The vessels are called nanosponges because of their nearly invisible size. Each nanosponge has a diameter of roughly 85 nanometers, with each nanometer measuring one billionth of a meter. Each is wrapped up in red cell membranes, and can survive for nearly two days in the bloodstream.
The research has been published in a variety of journals, and Zhang's work led the MIT Technology Review to name him last summer as among the top 35 young innovators in the world of 2013.
"None of this would be happening now if it were not for UC San Diego," Zhang said. "From the facilities to the students and the support, it has all been conducive to this type of research."