Researchers at Tufts University School of Engineering and the University of Pavia (Italy) have developed a three-dimensional tissue made from porous silk, that’s capable of producing platelets for clinical use. The development is expected to have a significant impact on treatment of blood diseases.
Platelets are cell fragments containing no nucleus, produced by megakaryocytes found in bone marrow. They’re an essential component in the blood clotting process, but can also play a role in strokes and heart attacks, making an increased understanding of their production an important area of investigation. In the study, researchers aimed to create an artificial bioreactor that mimics the microenvironment present in bone marrow, facilitating the artificial formation of platelets.
The new bioreactor system was constructed using microtubes of silk, fibronectin and collagen within a porous silk sponge. Active endothelial cells and related proteins that support platelet production were placed within the structure, which was then seeded with platelet-producing megakaryocytes.
The team used silk protein to mimic the microenvironment, as its unique molecular structure enables it to be modeled into a shape that encourages platelet formation. The material is non-activating, so doesn’t trigger the clotting process when platelets are present, allowing for easy collection of the cell fragments.
Tests showed that platelets resulting from the system were able to aggregate and clot, though the number produced was lower than observed in the human body. However, the system is scalable, allowing for increased production should future studies require it.
Given the wide range of diseases that affect platelet production, it’s thought that the development will have a significant impact on treatment, providing researchers with a platform for the study of platelet formation. The team hopes that the method will be used to produce platelets that can function as a source of growth factors, helping patients recover from ulcers, burns and other ailments.
"This patient-specific systems could provide new insight and options for clinical treatments," said David Kaplan, Chair of Biochemical Engineering and Stern Family professor at Tufts. "Further the platelets can be generated on demand, avoiding the complications of storage problems, and in greater quantities and with better quality and control in terms of morphology and function."
