Blood drives may someday become a thing of the past.
Scientific efforts to engineer artificial blood components took two big strides forward this week. On Monday, researchers from UC Santa Barbara and the University of Michigan published a study describing their synthetic red blood cells, which are capable of delivering medicine, oxygen or MRI contrast agents throughout the body.
The “cells” were made by layering hemoglobin and other proteins on top of doughnut-shaped scaffolds made of a polymer called polylactic acid-co-glycolide, or PLGA. When the researchers were done, they removed the polymer core and found that their new structures were just as flexible as authentic red blood cells, allowing them to squeeze through tiny capillaries.
The fake red blood cells were biodegradable and biocompatible. When the researchers soaked them in a drug called dextran, the “cells” released the drug “in a controlled manner,” according to the study. It also worked for the anti-coagulant heparin.
Meanwhile, another group of researchers is using nanotechnology to develop synthetic blood platelets that could help the body stem blood loss arising from traumatic injuries.
Platelets are instrumental in forming clots, which halt the bleeding from routine cuts and scrapes. But the body doesn’t make enough platelets to counteract the heavy bleeding that can result from car crashes, bomb blasts and other kinds of trauma.
To help out, Erin Lavik of Case Western Reserve University in Cleveland and her colleagues used biodegradable polymers to make fake platelets. When inside the bloodstream, they attach to real platelets, producing bigger clots that stand a better chance of halting bleeding, whether internal or external.
Rats that were injected with the synthetic polymer stopped bleeding faster than untreated rats, according to a study published today in Science Translational Medicine. The degree of improvement depended on how quickly the platelets were administered, but rats that got the platelets before they were even injured stopped bleeding twice as quickly as control rats.
The artificial platelets also outperformed recombinant factor VIIa, which is currently used to control bleeding in operating and emergency rooms, according to the study.
The researchers said their ultimate goal is to design synthetic platelets that can be stored at room temperature and administered through an IV. That would make them especially handy for military medics, who currently have few good options for stemming blood loss due to roadside bombs and other violent attacks.
-- Karen Kaplan
Photo: These synthetic red blood cells are almost as good as the real thing. In some ways, they're even better. Credit: Nishit Doshi/UC Santa Barbara