Nanosponges Could Soak up Toxins Released by Infections, Venom

A team of researchers at the University of California San Diego has created ‘nanosponges’ capable of removing a broad class of toxins from the bloodstream, including toxins produced by methicillin-resistant Staphylococcus aureus (MRSA), poisonous snakes and bees.

Left: schematic structure of a toxin nanosponge. Right: zoomed-in view of a single toxin-absorbed nanosponge, scale bar - 20 nm (Che-Ming J. Hu et al / Zhang Research Lab)

Left: schematic structure of a toxin nanosponge. Right: zoomed-in view of a single toxin-absorbed nanosponge, scale bar – 20 nm (Che-Ming J. Hu et al / Zhang Research Lab)

These ‘nanosponges,’ which thus far have been studied in mice, can neutralize pore-forming toxins, which destroy cells by poking holes in their cell membranes. Unlike other anti-toxin platforms that need to be custom synthesized for individual toxin type, the nanosponges can absorb different pore-forming toxins regardless of their molecular structures.

In a study, reported in the journal Nature Nanotechnology, against alpha-haemolysin toxin from MRSA (α-toxin), pre-innoculation with nanosponges enabled 89 percent of mice to survive lethal doses. Administering nanosponges after the lethal dose led to 44 percent survival.

“This is a new way to remove toxins from the bloodstream,” said Prof Liangfang Zhang, senior author of the study.

“Instead of creating specific treatments for individual toxins, we are developing a platform that can neutralize toxins caused by a wide range of pathogens, including MRSA and other antibiotic resistant bacteria.”

The study could also lead to non-species-specific therapies for venomous snake bites and bee stings, which would make it more likely that health care providers or at-risk individuals will have life-saving treatments available when they need them most.

Now the team is aiming to translate this work into approved therapies.

“One of the first applications we are aiming for would be an anti-virulence treatment for MRSA. That’s why we studied one of the most virulent toxins from MRSA in our experiments,” said Dr Che-Ming Hu, the first author on the paper.

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Bibliographic information: Che-Ming J. Hu et al. A biomimetic nanosponge that absorbs pore-forming toxins. Nature Nanotechnology, published online April 14, 2013; doi: 10.1038/nnano.2013.54