Implants 3D-printed in space could enable nerve regeneration

After 3D printing implantable medical devices aboard the International Space Station, Auxilium Biotechnologies has enrolled the first patient in a clinical trial of its technology for nerve regeneration.

San Diego-based Auxilium Biotechnologies designed the investigational NeuroSpan Bridge device to accelerate nerve regeneration and nerve targeting after debilitating nerve injuries to extremities. About 3% of civilian trauma cases and 30% of military trauma cases involve nerve injury, said Auxilium Biotechnologies CEO Jacob Koffler.

“Nerves don’t regenerate where they need to go. They do that very randomly, sometimes even going backward towards the proximal end,” he said in a Medical Design & Outsourcing interview. “What we have is a technology that is able to organize this regeneration, keep them in the same pathway and bring them to the original target that was denervated due to the injury.”

The NeuroSpan-1 pivotal study is for an anticipated FDA 510(k) clearance submission. It will include 80 patients with upper or lower extremity nerve injuries to compare the Auxilium Biotechnologies NeuroSpan Bridge against the Integra LifeSciences NeuroGen Nerve Guide and nerve autograft repair.

The NeuroSpan Bridge implants range from 1 cm to 3 cm in length and are made from what Koffler described as a biocompatible, degradable material that has been “known in biomedical research for many years.” He declined to name the material for competitive reasons.

Integra LifeSciences makes its NeuroGen Nerve Guide out of an absorbable Type 1 bovine collagen tube, and the NeuroSpan-1 study will exclude patients who are allergic to bovine products.

The clinical trial’s primary endpoints will measure the change in static two-point discrimination (2PD) at 12 months along with complications and adverse events. Secondary endpoints will measure motor function, sensory function, moving 2PD and Disabilities of the Arm Shoulder and Hand (DASH) scores. The study will also compared surgery times, pain scores and readmission rates.

3D printing implants in orbit

Auxilium Biotechnologies announced successful space experiments using its 3D bioprinter and proprietary biomaterial in February 2025, simultaneously printing eight miniature implants in two hours.

The company says its Auxilium Microfabrication Platform (AMP-1) is capable of manufacturing devices with “unmatched precision and efficiency” in orbit thanks to properties of microgravity that allow for uniform material distribution and fine, intricate structures.

“When we 3D print these devices [on Earth], the particles just sink, and we want uniform distribution,” Koffler said. “The idea is that in space we will get uniform distribution, and when that happens — again, this is the hypothesis — the nerve will experience these particles continuously as it grows through the device, instead of the particles being concentrated on one aspect of the device.”

The pivotal study won’t use devices printed in orbit, with Auxilium Biotechnologies planning to use that particular method later for a third-generation device that can “actively enhance regeneration using drug delivery,” Koffler said.

The microgravity 3D bioprinting technology could also have applications for spinal cord injuries and tissue engineering. A perfusable blood vessel the company printed (pictured here) could be used for tissue engineering of a thick piece of muscle to avoid necrosis in the center of that tissue, Koffler said.

The AMP-1 machine can print down to a single micron pixel and was used for 20 printing sessions on a single mission, including more than one session per day with multiple devices per session, Koffler said.

“We designed it to be very simple,” he said. “Integration of the printer in the space station literally took two minutes, which was a big advancement. Others that have tried to 3d print in space always perform one printing session per mission. … We are able to do mass production of medical devices in space. That’s really the key here.”

“In addition to that, the design of the printer is such that we have minimal involvement and need for astronaut time, because astronauts are very busy and astronaut time is very expensive,” he continued. “We remote control it from here, and the only astronaut time needed is to take a bio ink cartridge, put it in, close the door and then take it out at the end and put it in storage.”

The Auxilium Biotechnologies 3D printer is the first of its kind in space and doesn’t yet have a return date to Earth, Koffler said. The company is in talks with private companies building commercial space stations to keep the equipment in orbit even after the ISS is decommissioned sometime after 2030.

“A lot of people have been contacting us for the space work and are interested in trying and using our space capability to benefit their own science and projects,” Koffler said.

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