When patients on blood thinning drugs, such as heparin, need to undergo surgery, there is a risk that they might hemorrhage and uncontrollably bleed. Acting as an anti-coagulant, the drug prevents the formation of clots by blocking a particular protein found in the blood, though this can cause problems when under the knife. But now researchers have possibly developed a way round this, using a nanofiber hydrogel infused with snake venom.
“It's interesting that you can take something so deadly and turn it into something that has the potential to save lives,” said Jeffrey Hartgerink, who helped develop the hydrogel, in a statement. Hartgerink is a coauthor of the research, which is described in the journal ACS Biomaterials Science and Engineering. Called SB50, the new material can be injected at the site of the wound, where the nanofibers will reassemble into a gel, conforming to the site of the wound and stopping the flow of blood. During tests on rats in the lab, the researchers found that the SB50 can stem bleeding within an impressive six seconds.
Snake venom comes in a variety of different types. Some, containing neurotoxins, act on the nervous system and brain, leading to paralysis and death if not treated quickly; these are used predominantly by cobras, mambas and sea snakes. Puff adders, rattle snakes and bushmasters on the other hand use cytotoxic venom, which causes the site of the bite to swell up and the cells to die, leading to tissue necrosis.
The video shows how the venom from the Russell's viper can cause blood to coagulate and effectively form a jelly. SHARKSWHALESANIMALS's channel/YouTube
But some snakes have venom that affects the blood, and are thus known as hemotoxic. These can either be anti-coagulants as found in the boomslang snake of South Africa, causing uncontrollable bleeding, or coagulants as found in pit vipers of South America (and the Russell's viper, above). It is this last group of hemotoxins that has been of great interest to doctors for the past few decades, after the protein responsible for the clotting effect was identified as batroxobin, also known as reptilase. Since then, it has been used in medicine for a variety of different needs.
The problem with the blood thinner heparin is that once it has been administered, most other drugs used to trigger blot clotting don’t work in conjunction. “Heparin blocks the function of thrombin, an enzyme that begins a cascade of reactions that lead to the clotting of blood,” explains Hartgerink. “Batroxobin is also an enzyme with similar function to thrombin, but its function is not blocked by heparin. 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 new material SB50 is the first to use a combination of nanofibers and batroxobin, and it is hoped that the researchers will be able to get approval for it from the Food and Drug Administration before being able to test it in clinical trials.