Artificial platelets developed by a team of scientists may one day be able to save human lives!
While blood donations are low, platelet donations are even rarer. These cellular fragments, which are essential for blood clotting , have a short shelf life . While blood can stay refrigerated for up to a month, platelets survive for a week at most .
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To address this problem, scientist Ashley Brown and her team created an artificial platelet substitute that could be stored for long periods of time. In a recent paper in Science Translational Medicine, they describe using their synthetic platelets to stop bleeding and promote healing in rodents and pigs.
Natural platelets circulate in the blood and prevent or stop bleeding by forming clots. Sometimes, the body needs more of them. People with serious injuries, cancer , and certain chronic conditions that drain the blood of platelets often require transfusions. Typically, platelets are collected through a process called apheresis, in which a donor's blood is passed through a tube into a machine that separates the platelets. They are then collected in a bag, and the remaining blood is returned to the donor.
Their limited shelf life also means they are not often stocked in rural hospitals and cannot be easily transported. Brown's goal is to create an alternative that is easy to store and ship, that could be given to patients sooner, such as in an ambulance or on the battlefield, and regardless of blood type.
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To make their artificial platelets, Brown and her team used a water-based gel called a hydrogelto form nanoparticles that mimic the size, mechanics, and shape of natural platelets. They then designed an antibody fragment that binds to fibrin, a protein that helps platelets form clots, and added this fibrin antibody to the surface of the nanoparticles. When injury occurs, platelets rush to the site of damage to form a temporary plug. Fibrin is also activated in this process and accumulates at the site of injury, eventually creating a clot.
To find the optimal dose of artificial platelets needed to stop bleeding, the researchers tested a range of doses in mice. They then injected the artificial version into mice, rats and pigs and compared them with animals that received natural platelets and those that received no treatment. All of the animals in the study had severe internal bleeding. They found that the synthetic platelets were able to travel through the bloodstream to the site of the wound to promote clotting and speed healing.
Healing rates were similar in the animals that received synthetic platelets and those that received natural platelets. Overall, both groups fared better than those in the untreated group. Interestingly, the researchers only needed to use about one-tenth of the artificial particles to achieve the same healing effects as natural platelets.
In the recent study, researchers observed no negative health effects in animals given the synthetic substitute. Brown says the particles that travel through the animals' wounds likely end up in the scab that falls off when the wound heals.
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Another advantage of artificial platelets is that they can be freeze-dried and then rehydrated when needed. Human trials are just a few years away, and only then will scientists know if the synthetic platelets are ready for real-world use.
Source: wired
