Artist's impression of blood flow, including red and white blood cells and platelets (shown here in yellow). Synthetic platelets bind to natural platelets at the site of an injury, speeding up the clotting process.
Credit: iStockphoto
SYDNEY: Scientists have developed artificial platelets to enhance the natural process of blood clotting, reducing the risk of fatal blood loss on the battlefield and in the emergency room.
Platelets are colourless disc-shaped cells which activate the blood clotting process, helping to form 'plugs' which stop blood flowing from cuts and grazes. However, they are sometimes overpowered by serious injury or trauma, which can lead to fatal blood loss.
Platelets are currently supplied by blood donors and are required for a number of situations, including surgical bleeding, as well as for patients with blood disorders such as leukaemia.
The current technology used for controlling bleeding during surgery is called recombinant factor VIIa. This, however, carries with it issues of high cost and the risk of artificial blood clots leading to strokes, heart attacks and thrombosis.
Clotting on cue
Now, biomedical engineers at Case Western Reserve University in Cleveland, Ohio, have developed synthetic platelets made out of a material called PLGA, which is also used to make dissolving sutures.
The PLGA is shaped into small cores, to which strands of water-soluble polymers are attached. The polymers act as a shield, preventing potentially dangerous artificial clots from forming. Another molecule which binds to 'activated' natural platelets is then attached.
Natural platelets activated by injury release a chemical to which the synthetic platelets bind. This forms a larger clot which stems bleeding more quickly.
"The great thing about these particles is that they are very simple," said lead researcher, Erin Lavik, a biomedical engineer from Case Western Reserve University.
The work so far has been on rodents, so the researchers have yet to determine how the synthetic platelets will behave in people. "But we're very excited about the findings so far," said Lavik of the paper published in the journal Science Translational Medicine.
Portable platelets
At the moment, the main use the researchers see for synthetic platelets is on the battlefield, because of their comparatively long shelf life of several weeks, as opposed to the lifespan of natural platelets, which survive for around seven days. This makes them ideal for medics to keep in their field packs.
However, according to Joanne Joseph, a haematologist from St Vincent's Hospital in Sydney, there would be a potentially huge number of other uses for synthetic platelets, if they were proven effective.
"If someone could invent synthetic platelets, it would be fantastic. Platelet transfusions are used in all sorts of circumstances, not only in trauma and bleeding, but also for disorders such as leukaemia, and one of the main problems is supply. If you had something like this it would have overwhelming potential," she said.
