Organs in orbit: How bioprinting in space could unlock interplanetary travel

The development of additive manufacturing (3D printing) has advanced considerably in recent decades. Originally limited to rapid prototyping and creating plastic models, it is now commercially available for industrial production using various materials, including metal.

A major development is the emergence of 3D bioprinting , where layers of living cells are deposited to build three-dimensional organic structures. Since 2012, biotechnology firms and academic institutions have been researching this technology for biomedical purposes. Medical facilities may soon be able to fashion replacement organs, skin , vascular tissues , cartilage , brain tissue , and body parts using a patient’s stem cells.

The technology also has space applications. Space agencies and biotechnology companies are researching bioprinting aboard the International Space Station (ISS), where microgravity allows cell cultures to grow with greater ease. On Earth, bioprinting requires a scaffold or other structure (a gel medium or sugar matrix) to support tissues as they are being deposited. However, in the near-weightlessness of LEO, tissues grow in three dimensions without the need for support structures

This could revolutionize health care on Earth and advance human space exploration by reducing dependence on Earth-supplied resources.

Origins of bioprinting

The 3D bioprinting process traces its roots to trials conducted in 2003 by researchers from Harvard Medical School at Boston Children’s Hospital. The team built replacement urinary bladders by constructing scaffolds from collagen and synthetic polymer and then layering them with patients’ stem cells.

This led research fellow Anthony Atala to create the Wake Forest Institute for Regenerative Medicine (WFIRM) in 2004, where he currently serves as the G. Link Professor of urology. In the years following its foundation, WFIRM scientists successfully engineered several types of tissues and organs by hand and implanted them in patients as part of small clinical trials.

In addition, Atala and his colleagues began looking for ways to automate the process. Their experiments using a basic inkjet desktop printer led to the development of machines capable of printing customized scaffolds for human organs. This was followed by the development of the first 3D bioprinters – the Integrated Tissue and Organ Printing System (ITOP). As of 2012, the technology has become a focal point of research for creating biomaterials and organs.

Benefits of bioprinting

The primary goal is to solve the organ donor crisis by creating replacement organs. This could mean shorter wait times for transplants, organs tailored to patients’ genetics and physiology, and reduced risk of rejection. Patients may not need to take anti-rejection medications, avoiding their harmful side effects. These include elevated high blood pressure, diabetes, higher cholesterol, increased risk of infections, gastrointestinal side effects, and an increased risk of some forms of cancer.

While progress has been made, many challenges still need to be overcome before 3D bioprinting can be adopted for clinical use. Dr. Michaela Musilova , an award-winning astrobiologist, analog astronaut, researcher, and author, has conducted space-related research at institutions worldwide, including NASA, ESA, and CalTech. As she told Interesting Engineering via email, bioprinting in Low Earth Orbit (LEO) could help medical researchers overcome one of the leading issues:

“The demand for organ transplants is incredibly high, and being able to bioprint organs could help countless people with serious ailments. 3D bioprinting in space could truly revolutionize healthcare on Earth by allowing us to print organs in microgravity. When we try to print an organ, we’re working with individual cells that are incredibly fragile in their initial stages.

“On Earth’s surface, under 1g of gravity, these delicate structures tend to collapse under their own weight. But in microgravity, the destructive force is minimal, and we can print the fragile structures in a true 3D manner. This unique advantage enables cells to grow and assemble into complex, functional tissues in ways that just aren’t possible here on Earth.”

Experiments aboard the ISS

Research aboard the ISS began in 2014 with the 3D Printing In Zero-G investigation, which demonstrated that 3D printing with inorganic materials such as plastic worked normally in microgravity.

Between 2018 and 2020, the Russian state space agency (Roscosmos) conducted experiments aboard the ISS using a magnetic levitation bioprinter called Organ.Aut . These experiments showed that bioprinting in microgravity could create tissue constructs, helping to pave the way for additional research on producing artificial organs.

The European Space Agency (ESA) and the German Space Agency (DLR) also conducted an experiment aboard the ISS called Bioprint FirstAid . This consisted of a prototype for a portable handheld bioprinter that creates a customized patch from a patient’s own skin cells. This aimed to test bioprinting techniques that could compensate for how the healing process changes in microgravity. The device could prove vital to astronauts on long-duration missions to the Moon and Mars and also has extensive applications here on Earth.

NASA’s bioprinting research aboard the ISS occurs within the BioFabrication Facility (BFF), developed by the aerospace and space infrastructure company Redwire Corporation . This includes the BFF-Cardiac project, which uses the BFF to evaluate the printing and processing of cardiac tissue samples. The investigation could lead to the development of replacement heart tissue and, eventually, the creation of replacement hearts.

The BFF-Meniscus and BFF-Meniscus-2 investigations followed, which relied on Mesenchymal Stromal Cells (MSC) – stem cells isolated from bone marrow and other tissues – to create connective tissue. In the summer of 2023, this experiment successfully used MSCs to print a human knee meniscus. The experiment was conducted by the biomedical research division of the Uniformed Services University (4DBio3), intended to create improved therapies for injuries like meniscus tears that are common among service members.

There’s also the Protein-Based Artificial Retina Manufacturing experiment by LambdaVision Inc . in partnership with Space Tango Inc . This investigation aims to develop and validate space-based manufacturing methods for artificial retinas. On Earth, gravity affects the quality of the films that print layers of retinal proteins, but films created in microgravity are more stable and have higher optical clarity. This experiment successfully manufactured multiple 200-layer artificial retina films, and companies are now working to commercialize the hardware and develop strategies for other therapies and drugs.

“We humans already have a continuous presence on the International Space Station since 2000. However, this initiative will take us a step further toward becoming a truly spacefaring species with multiple people who call space their place of work,” Dr. Musilova said.

Applications for Earth and beyond

With the addition of bioprinting capabilities in space, crews may eventually be able to 3D print almost anything they need, including living tissue. The potential applications include musculoskeletal injuries, one of the most common injuries for athletes and military personnel, and improved treatments for crews who experience musculoskeletal injuries on future space missions.

Bioprinted artificial retinas could help restore sight for the 30 million worldwide suffering from retinal disorders and diseases. Bioprinting in microgravity could also produce cultured meat and medicine for future space missions. This would reduce reliance on food and medical supplies launched from Earth while helping maintain crew members’ health and safety throughout a mission.

Using cultured cells from the patient reduces the risk of rejection by the immune system, and the device offers greater flexibility in addressing wound size and position. Because the device is small and portable, healthcare workers could take it almost anywhere on Earth. The investigation showed that the device works as intended in microgravity, and researchers are studying the space-printed patches and comparing them with samples printed on the ground before taking the next step.

“To make this a reality, we’ll need to build infrastructure in low Earth orbit to house the 3D printing equipment and the humans who need to supervise it. The amazing implication of this is that it will open up a workplace in space where humans will work, with all the implications that such activity entails,” Dr. Musilova said.

“Furthermore, as a researcher focused on human hibernation for long-duration space travel, I see that the ability to replace aging organs could significantly reduce the biological limits on how long we can endure in space. By overcoming these limitations, we’re expanding our horizons and making extended space exploration more attainable than ever before,” she added.

The development of 3D printing has revolutionized manufacturing and industry as we know it, and its applications are now extending to space. This has the potential to revolutionize manufacturing further by introducing in-orbit assembly and in-space manufacturing (ISM), where everything from tools and replacement parts to entire spacecraft can be manufactured in space.

As one of the many spinoffs of this technology, bioprinting has the potential to extend this revolution further by allowing for the creation of replacement organs, tissues, biomaterials, and even food – all grown from cultured cells. This will have a significant impact on medical treatments here on Earth and will also facilitate the migration of people beyond Earth.

Bioprinting will not only allow for the replacement of organs for people suffering from the effects of space travel, but the capacity for producing organs, connective tissue, retinas, bones, and skin grafts on site will also allow humans to live longer, healthier lives in space and on other celestial bodies.