This work from Zhang's Nanomaterials and Nanomedicine Laboratory at the UC San Diego included nanoengineering post-doctoral researcher Che-Ming "Jack" Hu, nanoengineering graduate student Ronnie Fang, and bioengineering graduate student Brian Luk.
The researchers found that their nanosponge vaccine was safe and more effective than toxoid vaccines made from heat-treated staph toxin. After one injection, just 10 percent of staph-infected mice treated with the heated version survived, compared to 50 percent for those who received the nanosponge vaccine. With two more booster shots, survival rates with the nanosponge vaccine were up to 100 percent, compared to 90 percent with the heat-treated toxin.
"The nanosponge vaccine was also able to completely prevent the toxin's damages in the skin, where MRSA infections frequently take place," said Zhang, who is also affiliated with the Moores Cancer Center at UC San Diego.
Fighting Pore-Forming Toxins
This work is a twist on a project the UC San Diego nanoengineers presented earlier this year: a nanosponge that can sop up a variety of pore-forming toxinsfrom bacterial proteins to snake venomin the body.
Pore-forming toxins work by punching holes in a cell's membrane and letting the cell essentially leak to death. But when toxins attack the red blood cell membrane draped over the nanoparticle, "nothing will happen. It just locks the toxin there," Zhang explained.
The nanoengineers wondered what would happen if they loaded one of their nanosponges with staph toxin in this way, and presented the whole package to an essential part of the immune system called dendritic cells. Could the loaded particles trigger an immune response and work as a toxoid vaccine?
Staph toxin is so powerful that it kills immune cells in its unaltered form. Most vaccine candidates, there
|Contact: Daniel Kane|
University of California - San Diego