New nanosponge vaccine soaks up a dangerous pore-forming toxin produced by MRSA, say researchers.

Toxoid vaccines protect against a toxin or set of toxins, rather than the organism that produces the toxin(s). As the problem of antibiotic resistance worsens, toxoid vaccines offer a promising approach to fight infections without reliance on antibiotics.
"With our toxoid vaccine, we don't have to worry about antibiotic resistance. We directly target the alpha-haemolysin toxin," said Liangfang Zhang, a nanoengineering professor at UC San Diego Jacobs School of Engineering and the senior author on the paper. Targeting the alpha-haemolysin toxin directly has another perk. "These toxins create a toxic environment that serves as a defense mechanism which makes it harder for the immune system to fight Staph bacteria," explained Zhang.
Beyond MRSA and other staph infections, the nanosponge vaccine approach could be used to create vaccines that protect against a wide range of toxins, including those produced by E. coli and H. pylori.
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.
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Fighting Pore-Forming Toxins
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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.
Source-Eurekalert