Earth’s ultimate mission to put a man on Mars could be made safer by using 3D printing to create prosthetics for common hand injuries suffered by space crew.
Copper 3D has created an antibacterial material called Plactive, which can be used to treat injuries such as mallet finger – which can affect normal hand function and hinder space missions.
The US company has now received a grant – the value of which it hasn’t released – from the NASA Nebraska Space Grant Consortium, which aims to help enhance the quality of aerospace research, to test the properties of the additive-manufactured material on the International Space Station.
Why is 3D printing in space needed for prosthetics?
Dr Jorge Zuniga, assistant professor at the University of Nebraska Omaha’s Department of Biomechanics and lead scientist of Copper 3D’s project, said immune system dysfunctions are an issue for astronauts in long-term space missions like a voyage to Mars in particular, which could take three years.
He told Compelo: “Future long duration explorations missions to Mars will bring new challenges to the health and well-being of astronauts.
“In combination with potential host susceptibility due to dysfunction in the immune system, the risk of infection may be much higher in the spaceflight environment than in a normal workplace environment.
“Unfortunately, the direct cause of this altered immune behaviour has not been identified, but may be linked to radiation, microbes, stress, microgravity, altered sleep cycles and isolation.
“Using medical devices manufactured with an antibacterial material like Plactive can reduce the bacterial and immune risks associated with spaceflight.
“Furthermore, manufactured medical devices in space provides a solution to current risks and logistical obstacles observed in human spaceflight.
“Additive manufacturing in microgravity represent the first steps on the path toward sustainable and Earth-independent exploration initiatives.”
Why the Plactive material is an ideal 3D printing material for 3D printing in space
Chilean 3D printing materials company Copper 3D has set new standards in the additive manufacturing sector by developing antibacterial nanocomposites that fight bacteria for printed prosthetics.
One of them is the Plactive – an antibacterial thermal plastic with “active” properties that eliminates a wide range of infections and micro-organisms such as bacteria, fungi and viruses.
The product is already registered as a nanocomposite with the US Food and Drug Administration after a 3D printed prosthetic for US war veterans was clinically tested.
Dr Zuniga said: “Plactive is an antibacterial 3D printing filament that has shown to be up to 99.99% effective against staphylococcus aureus [germs commonly found on the skin or in the nose] and E. coli [bacteria in the intestines that can cause severe abdominal cramps, bloody diarrhoea and vomiting].
“These antimicrobial properties and the environmental safety of copper makes it an appealing replacement for silver and other antimicrobial compounds for the development of medical devices requiring microbial control.
“Additionally, a study reported that compounds containing silver may cause irritation and staining of the skin.
“Copper ions function by protein structural manipulation, inhibiting their biological activity, and permeabilisation [allowing liquids or gases to pass through] of plasma membranes.
“Copper also operates as a catalyst in the healing process of wounds as it plays a key role in the enhancement of angiogenesis, such as new formation of blood vessels.
New medical devices to treat common injuries for astronauts in space
Space exploration is fascinating, but scary. Astronauts are subjected to serious health problems and injuries due to the nature of their jobs, which involve extreme atmospheric conditions and environments, particularly during prolonged space missions.
Despite spacesuit designs evolving to protect astronauts from the harsh atmosphere of space, as they experience temperatures ranging dramatically from -129C to 121C, they can still suffer from “immune dysregulation and bacterial risks.”
Dr Zuniga said: “The most important feature of the medical devices produced with Plactive in micro-gravity is that they maintain the same antibacterial properties as they exhibit on earth.”
He said hand injuries, such as mallet finger, are the most common among astronauts in space.
This could adversely impact space missions as it can lead to permanent deformities affecting the normal hand function of crew members.
Therefore, antimicrobial 3D printed filament could be used for the “development of functional and effective antibacterial finger prostheses.”
He said: “Mallet finger injuries occur when the tip of the finger is compressed towards the hand. As the finger is compressed, the ligaments supporting the joints are stretched.
“Furthermore, surgical procedures are also predicted to occur in long-duration space missions.
“It is not possible to provide a full surgical capability because of mass, volume, skills, ancillary services, and cost constraints and uncertainties regarding which surgical disorders may occur.”
The procedure to manufacture antimicrobial 3D printed prosthetics will be a brief process that can be completed in hours, depending on the size and scaling.
Issues with surgical equipment for 3D printing in space
Astronauts living on the International Space Station are trained to deal with medical hazards, but not major emergencies that could require surgery.
It is reported the current go-to method for treating medical emergencies aboard the International Space Station involves returning astronauts to Earth as soon as possible.
While Copper 3D’s prosthetic will be tested on the station in the coming months, Dr Zuniga is concerned about any contamination that could be caused by a lack of sterilisation after surgical procedures.
He said: “Previous investigations have demonstrated the ability to 3D print surgical effective instruments on Earth with the intent of providing surgical capabilities for space mission.
“However, the major issue with the implementation of these devices is the complexity to perform sterilisation procedures required to minimise the risk of device contamination and development of infections.
“It is possible that the development of antimicrobial materials with higher strength and stiffness would provide the opportunities to explore the development of durable antimicrobial surgical tools and prevent infections.”
The future of antimicrobial materials for 3D printing in space
There is a critical need to develop a raw material for the development of a variety of antimicrobial medical devices to address the current supply chain problems involving the medical care in harsh medical environments.
Antimicrobial 3D printing materials will provide an attractive solution to solve these real-world problems, especially in austere environments.
Dr Zuniga envisions the uses of antimicrobial 3D printing materials, such as emerging thermoplastic polyurethane-based flexible materials, being a vital tool in the development of tissue-engineered scaffolds and other soft tissues including blood vessels and cardiac walls.
He added: “Their applications will not be limited to astronauts in the International Space Station but can also be used for military personnel in the battlefield for prevention of infections associated with combat-related injuries.
“Sterilisation and biocidal technology in combat support hospitals and emergency humanitarian relief settings must be capable of providing a wide range of ‘on-demand’ medical devices.
“Currently, the sterilisation of medical devices depends on large-chamber stream sterilisers introducing a significant logistical burden.
“Treatment of battlefield trauma presents the unique logistical challenge of providing sterile medical devices to medical personnel.
“Transport and supply constraints limit the quantity and variety of medical devices available in the field and sterilisation equipment is often not available to support the instruments required.”
