Researchers have created artificial platelets that can be utilized to halt bleeding and improve healing at the location of an injury. Although they have shown success in animal models, they have not yet started testing on humans.Transfusions are necessary for severe bleeding, surgery, or chemotherapy patients. Currently, platelets from blood donors, preferably with a matching blood type, are used in these cases. However, there is a shortage of platelets, limited shelf life, and specific storage requirements. “We’ve created artificial platelets that work for any blood type and are designed to go directly to the injury site to aid in healing,” explained Ashley Brown.The author of a paper on synthetic platelets and an associate professor in the joint biomedical engineering program at North Carolina State University and the University of North Carolina at Chapel Hill explained, “The synthetic platelets are also easy to store and transport, which means they can be given to patients in clinical situations sooner, such as in an ambulance or on the battlefield.”
The synthetic platelets are constructed from hydrogel nanoparticles that imitate the size, shape, and mechanical properties of human platelets. Hydrogels are water-based gels consisting of water and a small amount of polymer molecules.
According to Brown, the synthetic platelets they have developed are able to change their shape just like natural platelets.
The research team altered the surface of the synthetic platelets to include antibody fragments that can bind to a protein called fibrin, which the body synthesizes at the location of an injury to promote clotting.
Due to these antibody fragments, the synthetic platelets can move through the bloodstream until they reach the wound, where they can then perform their function.
The comments bind to the fibrin, and the artificial platelets speed up the clotting process.”
Furthermore, in addition to creating a clot within the fibrin network, the artificial platelets also work to contract the clot over time — similar to natural platelets.
“This accelerates the healing process, allowing the body to progress with tissue repair and recovery,” Brown explains.
The researchers initially proved the effectiveness of the antibody fragments through in vitro testing, as well as demonstrating that the antibody fragments and synthetic platelets could be produced at scales that would make them viable for larger-scale use.
The scientists then utilized a mouse model to establish the most effective dosage of man-made platelets needed to halt bleeding.
Following studies in both mouse and pig models proved that the artificial platelets traveled to the injury site, hastened clotting, did not cause clotting issues in other areas, and sped up the healing process.
“In the mouse and pig models, the rate of healing was similar in animals that were given platelet transfusions and those that were given synthetic platelet transfusions,” Brown explains. “And both groups had better outcomes than animals that did not receive any transfusion. We alsoThe researchers discovered that both mouse and pig models showed that the synthetic platelets could be safely cleared by the animals over time through their normal kidney function. No negative health effects were observed from the use of the synthetic platelets.
“Furthermore, based on our initial estimates, we expect that the cost of the synthetic platelets – if they receive approval for clinical use – would be similar to the current cost of platelets,” Brown explains.
“We are completing preclinical efficacy testing and are in the process of securing funding for preclinical safety work which should enable us to obtain approval.”The article “Ultrasoft Platelet-like Particles Stop Bleeding in Rodent and Porcine Models of Trauma” has been published in the journal Science Translational Medicine. The paper has co-lead authors Kimberly Nellenbach, Seema Nandi, and Emily Mihalko. Nellenbach and Nandi were former postdoctoral researchers in the joint biomedical engineering program at NC State and UNC, while Mihalko is a former Ph.D. student in the program. The paper was also co-authored by Jennifer Sollinger, laboratory manager in Brown’s lab, and Nina Moiseiwitsch, a former Ph.D. student in the joint biomedical program. The researchers aim to obtain FDA approval to begin clinical trials within two years.The engineering program at NC State and UNC includes Ana Sheridan and Sanika Pandit, who are currently pursuing Ph.D. degrees in the joint program. Drew Koch, a former graduate student at NC State, is also a part of the program. Additionally, Lauren Schnabel, a professor of clinical sciences in NC State’s College of Veterinary Medicine, and Jagathpala Shetty, Leandro Moretti, and Thomas Barker from the University of Virginia, Maureane Hoffman from Duke University, and Andrew Lyon from Chapman University are all involved.
Furthermore, Brown, Nandi, Lyon, and Barker are co-founders of SelSym Biotech, a start-up company focused on developing and marketing synthetic platelets for clinical use. Nellenbach is also a stockholder in SelSym Biotech.This study received funding from various sources including the National Heart, Lung, and Blood Institute (grants R01HL130918, R01HL146701, R01HL162809, and F30HL163869), the National Institute of General Medical Sciences (grant 1T32GM133366), the National Institutes of Health (grant T32OD011130), the Department of Defense (grant W81XWH-15-1-0485), North Carolina Biotechnology Translational Research Grant (TRG-573547), the National Science Foundation (grant 1847488), the American Heart Association (grant AHA18PRE33990338), the U.S. Department of Veterans Affairs, and the North Carolina State University Chancellor’s Innovation Fund.
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