Researchers develop material for 3D-printing bone

“Our 3-D structure has different levels of porosity that is advantageous for its physical and biological properties”, he said.

A hyperelastic bone in the shape of a section of the human spine, 3-D printed using an ink developed at Northwestern University. She’s interested in learning whether different types of bones or kinds of defects will require that they 3-D-print different kinds of shapes. They also healed a damaged skull of a rhesus macaque with the material, a process that also showcased a surgeon’s ability to perfectly cut the implants to size. “The ability to easily print customizable implants is a big advance and would offer a lot of opportunities in areas from plastic surgery to tumor removal and fix”. Adding a growth factor to the hyperelastic bone promoted healthy growth, the research reports.

The hyperelastic bone implants themselves largely consist of a naturally occurring mineral called hydroxyapatite – a form of calcium readily found in the human bone. The HB can be implanted under the skin as a scaffold for new bone to grow on, or used to replace lost bone matter altogether. The material can be used soon after printing, which means it’s possible that hospitals and doctor’s offices could have their own printers-allowing implants to be created and installed on demand. Lead researcher Ramille Shah says this places a particular strain on growing children who need repeated surgeries as they age.

The new material, which they call hyper-elastic bone, appears to act like natural bone in the body and can fix deformed bones and some injuries, the team reports in the journal Science Translational Medicine.

“One of the major challenges in tissue engineering, especially when it comes to larger sizes, is vascularization”, Shah said.

Researchers have developed a 3D-printed synthetic bone that overcomes numerous shortcomings of current bone grafting materials. “From what I can see, this is a really marvelous material because it’s both strong and pliable”, she says.

“Therefore, it can grow with the patient, and this eliminates the need for any later surgeries as is done with metallic plates or other metallic implants”. It is also highly porous and absorbent – which is crucial for bone graft material to encourage the growth of blood vessels into the surgery area.

The researchers attribute the success of the material to its unique properties.

To test their material, the team first tested their 3D-printed scaffold as a material to fuse spinal vertebrae in rats.

Yes, these 3D printed bones are bouncy – an unexpected feature that makes them more malleable during procedures.

To round things up, this hyper-elastic artificial bone is cheap, easy and fast to make, and can be stored without degrading for at least one year.

The team’s insight came from the idea of combining materials used in bioengineering with production approaches from industry, says Jakus, who has an academic background in metallurgy and explosive materials.

Photos via [Credit: Adam E. Jakus, PhD, A. Jakus et al., Science Translational Medicine (2016)], Adam E. Jakus, PhD, Credit: Rahkendra Ice / A. Jakus et al.