Bleeding on the battlefield and in routine surgery is controlled by a number of different products, all of which have drawbacks, such as the potential for excessive heat, blood clots and allergic reactions. But a new biodegradable protein solution able to stanch bleeding in mere seconds appears to also be nontoxic and long-lasting in animals. Researchers at the Massachusetts Institute of Technology and the University of Hong Kong developed a liquid made from short proteins, or peptides, that could repair severed optic nerves in hamsters and control brain bleeding in mice, as well as oozing from other types of wounds. The liquid apparently formed a fibrous network over the wound that stopped bleeding, although how the material works in detail is unclear. The liquid does not seem to form a conventional blood clot, the group notes in a study published online October 10 in Nanomedicine.