When an individual suffers a traumatic injury, or undergoes a surgical procedure, controlling bleeding is vital to prevent potentially life-threatening blood loss. The faster the bleeding is stopped, the less likely the patient is to go into shock which could be irreversible if enough blood is lost.
Although drugs and special gauzes to stop excess bleeding are already in existence, scientists have just come up with an innovative way to induce blood clotting that could one day be added to the repertoire of live-saving antihemorrhagic agents: synthetic platelets.
Platelets, or thrombocytes, are colorless blood cells that play a crucial role in blood clotting. They help to prevent blood loss by aggregating together into clumps and then plugging the hole in the blood vessel. These functions are known to be mediated by their shape, flexibility and ability to form close interactions both with each other and substances at the injury site. Armed with this knowledge, scientists endeavoured to closely mimic these important characteristics in the hope that it would yield an effective synthetic clotting agent.
Although early attempts only managed to capture one or two important platelet qualities, the latest copycats are virtually identical to natural platelets in terms of shape, size, flexibility and surface biochemistry. They were produced using an additive nanoparticle manufacturing process, which involved building up layers of both synthetic molecules and biologically relevant proteins such as natural clotting factors. When compared with earlier, more rigid models, the newly designed disk-shaped nanoparticles were superior in terms of clumping properties. Furthermore, by adorning them with sticky proteins that interact with both natural molecules involved in hemostasis (the process of stopping bleeding) and proteins found at injury sites, the researchers were able to overcome previous targeting issues which limited their efficiency.
As described in the journal ACS Nano, when the synthetic platelets were put to the test in injured mice, they were found to be capable of successfully and rapidly inducing blood clots in the animals. When compared with no treatment, the nanoparticles stopped bleeding almost three times faster than the natural rate achieved by bodily processes alone.
In addition to potentially serving as an effective clotting agent to control bleeding in injured patients and individuals with clotting disorders, the nanoparticles’ designers believe that they could also one day be used as a novel drug delivery system for treating various conditions, such as atherosclerosis (hardening and narrowing of arteries). However, the researchers still need to do some tweaking before they can come close to human trials since the designer platelets seemed to induce the formation of tiny blood clots in the animal's lungs.
