The Brazilian Lancehead, above, is one type of South American pit viper whose venom contains Batroxobin, an enzyme that has been used to clot blood since 1936. Photo by Greg Hume/Wikimedia
HOUSTON, Nov. 11 (UPI) -- Surgeries may become safer for people who take blood-thinning medications, according to researchers at Rice University who found snake venom in hydrogels can be used as an effective clotting agent whether or not a patient is on an anti-coagulant.
Anti-coagulant and blood thinning drugs are used with patients who have cardiac conditions or are at risk for stroke. In surgical patients who take these drugs, doctors can apply pressure or use sutures, foams or adhesives to control bleeding and promote blood to clot after surgery but these can include toxic ingredients or spur an allergic reaction.
The researchers found combining Batroxobin, an enzyme found in the venom of two types of South American pit viper, with a hydrogel called SB50 allowed for quick healing of surgical wounds in lab experiments.
"Controlling perioperative bleeding is of critical importance to minimize hemorrhaging and fatality. Patients on anticoagulant therapy such as heparin have diminished clotting potential and are at risk for hemorrhaging," researchers wrote in the study, published in Biomaterials Science and Engineering. "This snake venom-loaded peptide hydrogel can be applied via syringe and conforms to the wound site resulting in hemostasis. This demonstrates a facile method for surgical hemostasis even in the presence of anticoagulant therapies."
Researchers loaded Batroxobin, which has been used as a coagulant since 1936, into a syringe with synthetic, self-assembling nanofibers that resemble a gel when injected at the site of a wound. In testing with rats being treated with heparin, the gel closed wounds in between 6 and 20 seconds and stayed closed after further "prodding" of the sites.
In addition to the venom-spiked gel, researchers tried the hydrogel with Batroxobin, Batroxobin without hydrogel, and two other hemostats that act like the researchers venom-containing hydrogel and found they didn't work as well.
"Heparin blocks the function of thrombin, an enzyme that begins a cascade of reactions that lead to the clotting of blood," said Jeffrey Hartgerink, a chemist at Rice University, in a press release. "Batroxobin is also an enzyme with similar function to thrombin, but its function is not blocked by heparin. This is important because surgical bleeding in patients taking heparin can be a serious problem. 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."
Further testing will be needed before the Food and Drug Administration will approve SB50 for use because, researchers said, because while Batroxobin has approval SB50 does not.