By Betty Coffman, UofL News
LOUISVILLE, Ky. — Technologies in development by researchers at the University of Louisville are aimed at ensuring astronauts on long-range space missions have access to medical care. A UofL research team recently tested rehydrating dried red blood cells in a weightless environment. The UofL group completed more than 50 weightless cycles during two flights to test rehydrating the blood and the use of 3D-printed surgical instruments aboard a ZERO-G aircraft.
ZERO-G is a privately owned company that uses a modified Boeing 727 jet to create a weightless environment using parabolic flight patterns. The experiments, sponsored by NASA, are designed to ensure that crews have access to proper medical treatment during long-range exploration space flights, such as to Mars.
Michael Menze, Ph.D., associate professor of biology, and Jonathan Kopechek, Ph.D., assistant professor of bioengineering at UofL, lead a team that has developed several methods for drying blood to enable it to be stored for long periods of time without refrigeration. The dried blood then can be rehydrated using sterile water when it is needed. Current methods for storing blood require constant refrigeration and the blood can only be stored for six weeks, which would not be sufficient for crews on years-long space missions.
“If cosmic radiation reduces red blood cell count, for example, you are not going to have a donor and a recipient [with a four-person flight crew], you are going to have four people needing blood and there is no good way to store it during a long space trip of months or years,” said Brett Janis, a graduate research assistant who also is involved in the project. “So being able to store it in a dried state and then confidently rehydrate it is critical.”
The dried blood is typically rehydrated by adding water and inverting the container, Menze said. This method relies on normal gravity, however, so the researchers devised other methods for potential use in space.
To develop testing procedures, Menze worked with George Pantalos, Ph.D., professor in the Department of Cardiovascular and Thoracic Surgery. Pantalos tested medical equipment in a weightless environment in the past and customized a glovebox enclosure he developed for his research for these experiments.
“If you are in reduced gravity or zero gravity, will the red blood cells rehydrate correctly and will they function like normal red blood cells, transporting oxygen to the tissues of the body,” Pantalos said.
Pantalos, Menze and Janis, along with other researchers and five students, designed and prepared the tests to rehydrate the blood cells and traveled to Florida with the glovebox and equipment in November 2019 to conduct the experiments aboard the ZERO-G aircraft. During the tests, the team assembled a bag with the powdered blood cells, a syringe and sterilized water in the glovebox. There they tested multiple techniques to rehydrate the cells during the weightless phases of flight.
“We tested two different ways of assisting in the mixing of liquid and powdered red blood cells,” Menze said. “We used pliable plastic bags instead of hard-plastic containers for the mixing. The water was added to the bag from an attached syringe and the liquid and powder were mixed by ‘massaging’ the bag or by using a second attached syringe and moving the liquid in and out of the bag. The ‘massage’ methods seem to work a bit better.”
Pantalos said the glove box and planned experiment techniques worked well, allowing the scientists and students to complete all the planned tests on the blood cells, which had been dehydrated using two different methods — spray-dried and freeze-dried — in 5 milliliter and 10 milliliter volumes. After the aircraft landed, the rehydrated samples were analyzed by a ground crew for evaluation to see if they are suitable for infusion into a patient.
“We found that the oxygen-carrying capacity of the blood was comparable to what we find when we are rehydrating our blood at one-earth gravity,” Menze said. “I was really excited.”
During the flight, Pantalos also tested the use of 3D-printed instruments to simulate basic surgical tasks such as incision and retraction. By 3-D printing tools and instruments they need aboard the spacecraft, it is possible for the crew to take basic materials and create specific pieces according to needs that arise during the mission rather than trying to anticipate all potential medical needs in advance.
The NASA Flight Opportunities Program, which supports projects for developing technology appropriate for use in space flight, funded the preparation testing and the flights. The UofL team now is preparing for their next flight campaign, planned for later this year, to test rehydration processes for cells dehydrated using different methods and rehydrating up to 350 milliliters of blood, which would be needed in an actual transfusion therapy situation.