The discovery, published in the January 1 edition of Experimental Hematology, could avoid shortages in donated blood platelets and reduce the significant costs associated with processing them for use by patients.
Many countries around the world are experiencing shortages in platelets and other blood products as blood donations can be unreliable. With a shelf life of just five days, platelet supplies are particularly sensitive to intermittent declines in donations, as can occur during holiday periods or in the flu season.
Aside from their short shelf life, donated platelets have a number of other drawbacks. They require a huge logistical effort to collect, and also expensive methods required for collection, processing and testing for pathogens.
Researchers have produced platelets in the lab in suspension, in plastic vessels or on ‘feeder layers’ of other cells. However, these have tended to give low yields of platelets that do not survive for very long, according to the scientists, led by Larry Lasky, associate professor of pathology at Ohio State University.
His team’s approach has been to use hematopoietic stem cells grown in a three-dimensional scaffold system made of a hydrogel or surgical-grade woven polyester fabric. The system does not require a feeder layer but does rely on coating the scaffold with platelet-boosting cytokines such as thrombopoietin and fibronectin.
After a few days, large bone marrow cells that produce platelets, called megakaryocytes, were produced in the culture system.
“We found production of functional platelets over 10 days with two-dimensional, 24 days with 3D scaffolds in wells, and more than 32 days in a single-pass 3D perfusion bioreactor system,” commented the authors, led by Larry Lasky of Ohio State University. They are now refining the technique to attempt to boost platelet yields.
Estimates are that it costs about $400 to harvest enough platelets for a single transfusion. Around 13 million platelet concentrates are collected annually in the US at a cost of about $1bn.