Synthetic Platelets May One Day Stop Bleeding in Trauma Patients
Case Western Reserve University researchers have developed synthetic platelets that could someday soon be used to help slow internal bleeding, saving lives of both civilian and battlefield trauma.
Blood loss is often the major cause of death in both civilian and battlefield traumas. Methods to stop bleeding include pressure dressings and absorbent materials such as QuikClot which effectively halts bleeding by absorbing large quantities of fluid and concentrating platelets to augment clotting. These treatments are limited to compressible and exposed wounds.
An ideal treatment would halt bleeding only at the injury site, be stable at room temperature, be administered easily, and work effectively for internal injuries. This may become a reality with synthetic platelets.
Erin Lavik and colleagues used a rat model to show that the injected synthetic platelets stopped internal bleeding after an injury 23 percent faster than in untreated rats. Their research has been published online in the journal Science Translational Medicine today.
Rats injected with the platelets prior to injury stopped bleeding in half the time of the untreated animals.
"It's tremendously exciting," Lavik said. "It's early data and there are a lot of experiments that still need to be done, but the early work is promising and we're excited about it."
Lavik and colleagues spent six years developing synthetic platelets based on Arg-Gly-Asp functionalized nanoparticles. The synthetic platelets have three layers; at the core is a material used in dissolvable stitches; surrounding the core is a layer of water soluble polymers that keeps the synthetic platelet from sticking to other platelets; the outermost layer has a molecule that helps it bind to naturally occurring platelets, augmenting the body's own clotting process.
The synthetic platelets were cleared within 24 hours at a dose of 20 mg/ml, and no complications were seen out to 7 days after infusion, the longest time point studied.
The synthetic platelet is in powder form and is stable at any temperature. Test results showed the platelets remain viable after sitting on a shelf for at least two weeks.
These synthetic platelets may be useful for early intervention in trauma and demonstrate the role that nanotechnology can have in addressing unmet medical needs.
"With trauma, the faster you can intervene the better the outcome is likely to be, so if you could have something that's safe and effective and could be carried in a medic's bag and administered in a simple way, you could potentially have a big impact on treating trauma."
There is still a long path ahead before the platelets will be ready for human use, Lavik said. The injections have to be tested on a larger animal model which can more closely mimic a human injury before they can move to human trials.
Intravenous Hemostat: Nanotechnology to Halt Bleeding; Sci Transl Med 16 December 2009: Vol. 1, Issue 11, p. 11ra22; DOI: 10.1126/scitranslmed.3000397; James P. Bertram, Cicely A. Williams, Rebecca Robinson, Steven S. Segal, Nolan T. Flynn and Erin B. Lavik