Problem: Scientists have worked for years to increase the longevity of targeted drugs, which promise to deliver treatment to a specific tissue within the body. These targeted treatments require new drug carriers such as polymers that are designed to evade the immune system. But too often, these carriers are destroyed before the drug can effectively target tumors and other localized sites of disease. Though the body’s own cells are protected from the immune system by their protein-studded outer membrane, it’s not possible to re-create this complex matrix for synthetic particles used in drug delivery.
Solution: Why not cloak therapeutics in natural membranes? That’s the idea of Liangfang Zhang, a nanoengineering professor at UC San Diego.
Zhang derives red-blood-cell membranes from blood samples and uses them to coat polymer nanoparticles. Because these particles look like red blood cells on the surface, they can fool the immune system; loaded with drugs, they serve as robust and long-lived drug carriers. An unexpected bonus: they can also act like nanoscale sponges to suck up toxic proteins produced by infectious bacteria or introduced by snake or insect venom. If the particles flood the bloodstream, they will divert most of the toxin away from actual cells.
Born in Wuwei County, 45 minutes by plane from Shanghai, Zhang left home for the prestigious Tsinghua University in Beijing when he was just 15. By the time he was 20 years old, he could have opened a factory to produce exceptionally tough rubber materials he’d helped invent as a student. But Zhang says he “didn’t want to run a rubber factory all my life.” And he knew if he started a factory, some other young upstart would come up with a better technology and he might not be able to compete. So he decided to pursue an advanced graduate degree in engineering in the United States. Despite his accomplishments as a scientist, however, he has never lost his desire to turn laboratory advances into practical breakthroughs.