Hartgerink, PhD, (left)
and Vivek Kumar, PhD
Photo courtesy of
Jeff Fitlow/Rice University
A nanofiber hydrogel infused with snake venom can stop bleeding quickly, even in the presence of anticoagulants, according to researchers.
The hydrogel, SB50, incorporates batroxobin, a venom produced by 2 species of South American pit viper.
SB50 can be injected as a liquid and transforms into a gel that conforms to the site of a wound, keeping it closed and promoting clotting within seconds.
The researchers described this hydrogel in ACS Biomaterials Science and Engineering.
Batroxobin was recognized for its properties as a coagulant in 1936. It has been used to remove excess fibrin proteins from the blood to treat thrombosis and as a topical hemostat. It has also been used as a diagnostic tool to determine blood-clotting time in the presence of heparin.
“From a clinical perspective, that’s far and away the most important issue here,” said study author
Jeffrey Hartgerink, PhD, of Rice University in Houston, Texas.
“There’s a lot of different things that can trigger blood coagulation, but when you’re on heparin, most of them don’t work or they work slowly or poorly. The use of batroxobin allows us to get around this problem because it can immediately start the clotting process, regardless of whether heparin is there or not.”
The batroxobin combined with the researchers’ hydrogels isn’t taken directly from snakes, Dr Hartgerink noted. The substance used for medicine is produced by genetically modified bacteria and then purified, avoiding the risk of other contaminant toxins.
The researchers combined batroxobin with their synthetic, self-assembling nanofibers, which can be loaded into a syringe and injected at the site of a wound, where they reassemble themselves into a gel.
Tests showed the new material stopped a wound from bleeding in as little as 6 seconds, and further prodding of the wound minutes later did not reopen it.
The researchers also tested several other options: the hydrogel without batroxobin, the batroxobin without the hydrogel, a current clinical hemostat known as GelFoam, and an alternative self-assembling hemostat known as Puramatrix. None of these options were as effective, especially in the presence of anticoagulants.
The new work builds upon the researchers’ development of injectable hydrogel scaffolds that help wounds heal and grow natural tissue. The synthetic scaffolds are built from the peptide sequences to mimic natural processes.
“We think SB50 has great potential to stop surgical bleeding, particularly in difficult cases in which the patient is taking heparin or other anticoagulants,” Dr Hartgerink said. “SB50 takes the powerful clotting ability of this snake venom and makes it far more effective by delivering it in an easily localized hydrogel that prevents possible unwanted systemic effects from using batroxobin alone.”
