"The more you heat it, the safer the toxin is, but the more you heat it, the more you damage the structure of the protein," Zhang explained. "And this structure is what the immune cell recognizes, and builds its antibodies against."
The nanosponge toxoid vaccine gets around this problem by detainingbut not changingthe staph toxin. Like a dangerous but handcuffed prisoner, the staph toxin can be led to the dendritic cells of the immune system without causing any harm.
Before this, "there was no way you could deliver a native toxin to the immune cells without damaging the cells," Zhang said. "But this technology allows us to do this."
Each vaccine particle is approximately 85 nanometers in diameter; for comparison, about 1000 of them would fit across the width of a single human hair. They are cleared from the body after injection in about two weeks, the researchers found.
Staph bacteria are one of the most common causes of skin infections, and can cause blood poisoning and surgical infections as well as pneumonia. According to the Centers for Disease Control and Prevention, about 80,000 Americans suffer from invasive MRSA infections each year, and over 11,000 of those individuals die. At the moment, there are no vaccines approved to protect humans against the toxins associated with staph infections, including those caused by MRSA strains.
The idea for a staph vaccine came about when the researchers considered the success of their nanosponge. If the particle was so good at collecting toxins, they wondered, what were the potential uses of a particle full of toxin? "To be honest, we never thought about the vaccine use from the beginning," Zhang noted. "But when we do research, we
|Contact: Daniel Kane|
University of California - San Diego