The European Space Agency (ESA) has started immediately project to 3D-print skin and bone tissue in space. The European Space Agency expects the ability to print human tissue in space could help keep astronauts healthy on their way to Mars.
ESA wants to carry out a manned mission to Mars by 2030. A major challenge here is the relatively long time astronauts spend in space. "A trip to Mars or other interplanetary destinations mean a stay of several years in space," explains Tommaso Ghidini, head of ESA's Structures, Mechanisms and Materials Division. "The crew faces many risks, and returning home early will not be possible. Bringing enough medical supplies for all possible incidents is impossible in view of the limited space and size of the spacecraft."
Responding to medical emergencies
"3D bioprinting allows them to respond to medical emergencies as they arise. For example, in the case of burns, new skin can be bioprinted, instead of taking skin away from another location on the astronaut's body. This creates secondary injuries that do not easily recover in space."
Another example mentioned is a bone fracture, something that is more likely to occur in space due to weightlessness and its impact on the human body. In this case, ESA wants to be able to print new bone tissue to repair broken bones.
Bioink
To make this possible, the ESA is experimenting in collaboration with scientists from the University Hospital of Dresden University of Technology (TUD). The parties are part of a consortium that also involves subcontractor OHB Systems and life sciences specialist Blue Horizon. "Skin cells can be bioprinted using human blood plasma as a bioink rich in nutritional value - easily available through crew members of the mission," explains Nieves Cubo, PhD Fellow in Bioprinting at the TUD.
"Plasma, however, has a very liquid consistency, which makes it difficult to work with it under different gravity. We have therefore developed a modified recipe by adding methyl cellulose and alginate to increase the viscosity of the substrate. Astronauts can find these substances in plants and algae, which is a viable solution for an independent space expedition."
Printing bone cells
Bone cells the researchers created by printing human stem cells in a similar bioink. This ink consists of stem cells combined with a cement consisting of calcium phosphate bone as a structure-supporting material, which is eventually absorbed by the human body during the growth phase.
Testing such printing techniques intended for space is not easy, as mimicking weightlessness in space on Earth is difficult. The techniques were therefore tested by printing both skin and bone tissue upside down. The researchers call this 'minus 1G' testing method the best option to demonstrate that their printing technique is feasible in space.
The researchers will further develop their development in the coming period. This will include which facilities are needed in a spacecraft to enable tissue printing. This includes not only the 3D printer itself, but also an operating theatre and sterile space to implant the printed tissue. The researchers also want to make the printing technology suitable for printing other tissues and eventually even entire organs.
Other parties also working on bioink
For some time now, several parties have been focusing on 3D printing tissues. For example, a group of researchers from the Fraunhofer Institute for Interfacial Engineering and Biotechnology (IGB) is working on bioink that will allow biologically functional tissue to be printed. With this tissue, the researchers aim to replace irreparably damaged tissue. Researchers at US Rice University have succeeded in printing osteochondral tissue using a 3D printer. This tissue can be used to treat patients with osteochondral injuries - where both bone and cartilage are damaged.
US company TechShot announced in January that it will send a 3D printer to the International Space Station (ISS) to print heart tissue. Printed organs tend to collapse under their own weight during printing. With weightlessness in space, TechShot hopes to have found a solution to this problem.
Author: Wouter Hoeffnagel
