Surgeons See Success With Experimental 3D-Printed Bone Grafts

Researchers implant 3D-printed bone scaffolds in rats and a monkey

2 min read
Close-up photograph of a small region of the first several top layers of 3D-printed hyperelastic human spine
Researchers hope to move to human clinical trials in five years with hyperelastic bones. Trials likely won't begin with anything as complex as this 3D-printed human spinal section, however.
Adam E. Jakus

Researchers have developed a 3D-printed synthetic bone that overcomes many of the shortcomings of current bone grafting materials. Surgeons successfully used the substance to fuse the spines of rats and repair a skull defect in a monkey, the researchers reported today in Science Translational Medicine.

The novel biomaterial is strong, elastic, and capable of helping the body regenerate new bone on its own. Most importantly, the material isn’t brittle, a property that could allow surgeons to trim a piece to fit the patient without it crumbling—a common problem with other synthetic bone constructs.

To achieve the effect, researchers used the right combination of starting materials for the ink and printed it at room temperature rather than with heat or lasers, explains Ramille Shah, principle investigator on the paper and biomaterials scientist at Northwestern University.

Shah’s team used a type of bioactive ceramic called hydroxyapatite—a material commonly used in attempts at regenerating bone—and added a polymer called polycaprolactone. Then, rather than using hot-melt or laser-based 3D printing, the team used a solvent-based, room-temperature 3D printing technique that relied on a unique combination of three solvents.

That improved the microstructure of the ink, says Shah. “It doesn’t dry out right away. It’s a little wet which allows each layer to adhere to the previous one,” she adds. The team dubbed their substance “hyperelastic bone.” The printer they used, called the 3D-Bioplotter System by EnvisionTec, is commercially available and costs US $250,000–$300,000, Shah says.

In the rat and monkey experiments, the printed scaffold integrated well into the animals’ bodies. Blood vessels moved into the porous material quickly, and the animals’ immune systems didn’t seem to reject the implant. Over time, the material is expected to biodegrade as the body’s cells naturally regenerate new tissue and replace the synthetic scaffold.

The substance could be particularly beneficial to children who need bone grafts, since it essentially grows with the child, says Adam Jakus, a postdoc in Shah’s lab and an author of the report.

Researchers have 3D printed bone-like material for other purposes, such as medical modeling. Paleontologists have 3D printed replica dinosaur skeletons and other scientists have created human skeleton replicas and biomimetic robot hands.

Implanting 3D-printed materials into the human body, however, requires orders of magnitude more testing and development. Shah wants to move the printed biomaterial into human clinical trials within five years. The U.S. Food and Drug Administration (FDA) has not yet approved a 3D-printed substance for use as a regenerative bone material, Jakus says. They hope hyperelastic bone will be the first.

The Conversation (0)

Are You Ready for Workplace Brain Scanning?

Extracting and using brain data will make workers happier and more productive, backers say

11 min read
A photo collage showing a man wearing a eeg headset while looking at a computer screen.
Nadia Radic

Get ready: Neurotechnology is coming to the workplace. Neural sensors are now reliable and affordable enough to support commercial pilot projects that extract productivity-enhancing data from workers’ brains. These projects aren’t confined to specialized workplaces; they’re also happening in offices, factories, farms, and airports. The companies and people behind these neurotech devices are certain that they will improve our lives. But there are serious questions about whether work should be organized around certain functions of the brain, rather than the person as a whole.

To be clear, the kind of neurotech that’s currently available is nowhere close to reading minds. Sensors detect electrical activity across different areas of the brain, and the patterns in that activity can be broadly correlated with different feelings or physiological responses, such as stress, focus, or a reaction to external stimuli. These data can be exploited to make workers more efficient—and, proponents of the technology say, to make them happier. Two of the most interesting innovators in this field are the Israel-based startup InnerEye, which aims to give workers superhuman abilities, and Emotiv, a Silicon Valley neurotech company that’s bringing a brain-tracking wearable to office workers, including those working remotely.

Keep Reading ↓Show less