An ‘artificial’ approach to saving lives

Blood is precious—and we’re running out of it. In some instances, the people who are saving lives can’t get the blood available to where it’s needed most.

Andre Palmer researches the creation of artificial blood—materials that replace lost blood—in an effort to combat those shortcomings.  During periods of blood shortages and/or high demand, such as in natural disasters, accidents, or when time is too limited to screen for patient blood type compatibility (such as in certain rural areas or on the battlefield), artificial blood products could offer medical professionals more flexibility in treating people in need of blood.

“If you have a car accident victim who lost blood, you can stop the bleeding in the victim and transfuse them with our materials which should replace the lost blood and keep them alive for up to 24 hours, which is more than enough time for them to get to a hospital to get a blood transfusion,” said Professor Palmer, who is also Ohio State’s associate dean for research in the College of Engineering and an Ohio Eminent Scholar in the William G. Lowrie Department of Chemical and Biomolecular Engineering. “The passion for this work comes from the fact that, if successful, these materials we’re developing could be used to save patients’ lives.”

‘An impending crisis’ with blood supply

Getting enough blood to locations when and where it is needed is complicated by storage and transportation issues. Blood must be stored at refrigerated temperatures and then matched based on blood type. An advantage of Palmer’s materials is that they can be stored at room temperature and are universal matches with any blood type.

Another obstacle? Donated blood is only good for 42 days whereas artificial blood can be stored for several years.

4.5 million

Number of Americans that need a blood transfusion each year

There’s another major problem with donated blood: We’re running out of it.

Each year, 4.5 million Americans need a transfusion. Every day, 29,000 units of red blood cells and 6,500 units of plasma are needed in the U.S. 

“We have an impending crisis,” Palmer said. “Transfusions are increasing while donations are decreasing. It’s estimated that by 2030, there will be a shortage of about 4 million units of blood in the US.”

Artificial blood can’t fix this problem completely because it’s only good for 24 hours once administered. But it can be of critical assistance in emergency situations by providing a stopgap as a person in need of blood awaits a transfusion. 

A better artificial blood

With his artificial blood in preclinical development, Palmer is succeeding where many have failed.

“The passion for this work comes from the fact that, if successful, these materials we’re developing could be used to save patients’ lives.” 

-Ohio Eminent Scholar and Professor and Associate Dean for Research in the College of Engineering Andre Palmer

“A lot of companies put millions of dollars into trying to develop a product, and they did not get anywhere,” said collaborator Pedro Cabrales, a professor of bioengineering at the University of California, San Diego. “Andre has been able to generate new ideas, moving his formulations closer and closer to clinical studies.

“There are others trying novel approaches, but I don’t think they have the same ability to scale up production to make it financially or physically viable the way Andre’s research is doing," Cabrales said.

In his most recent study, which was supported by the National Institutes of Health and published in the journal Biomacromolecules, Palmer and his researchers found that the key is to make the artificial blood molecules big enough so they don't leak from blood vessels and cause dangerous cardiovascular side effects such as high blood pressure and tissue injury.

"With bigger red blood cell substitute molecules you have fewer side effects," said Alisyn Greenfield, lead author of the study and a doctoral student who is advised by Palmer. "There's even a particular size range that has better benefits when it comes to the kind of cardiovascular effects that were seen with previous generations of the material," she said.

The researchers tested a red blood cell substitute called polymerized human hemoglobin – PolyhHb. Previous commercial versions explored in clinical settings did not receive FDA approval due to their many side effects. 

To find a better solution, Palmer's team focused on identifying the best size of PolyhHb by synthesizing material in four different-sized brackets and exploring the cardiovascular response in guinea pig models. Findings showed that the largest-sized brackets did not escape the blood vessels, thus avoiding blood vessel constriction and ensuing high blood pressure.

“There are others trying novel approaches, but I don't think they have the same ability to scale up production to make it financially or physically the way Andre's research is doing.”

Professor of Bioengineering Pedro Cabrales, University of California, San Diego

Collaborations will save lives

Palmer's research efforts involve collaboration with other labs, such as the laboratory of Pedro Cabrales at UC-San Diego. Palmer engineers the materials and Cabrales’ lab evaluates and finds biomedical applications for the materials. For instance, Cabrales is investigating whether an oxygen carrier Palmer created could work for someone suffering from hemorrhagic shock or who has severe anemia. It’s been a partnership that has lasted more than a decade and produced dozens of papers.  

“Andre has a really good work ethic. He gets things done and has very good ideas,” Cabrales said. “Probably he’s one of the most recognized scientists working on artificial blood right now. And he’s doing very noble work in transfusion medicine, which is a field very dependent on blood and blood supply.”

Along with his research in artificial blood, Palmer is researching how the biomaterials he creates can be used to improve organ transplantation. He is collaborating with Ohio State transplant surgeons Bryan Whitson and Sylvester Black to study how organ transplant methods can be improved.

Currently, donated organs are put on ice to lower the metabolic rate for storage prior to transplantation.

“We hypothesize the organ would function better if, instead of putting it on ice, you perfused the organ with a solution that could transport oxygen that would keep the organ more viable and it would function better when transplanted into a recipient,” Palmer said. “It could potentially improve transplant outcomes.”

-Based on stories by Ross Bishoff, Ohio State Impact, and Tatyana Woodall, Ohio State News