3D Printed synthetic bone grafts aim for human trials in five years

Researchers are currently working with a new 3D printed synthetic bone that the scientists say overcomes some of the issues that surgeons have with current bone grafting materials. In trials, the surgeons on the research team have used the substance to fuse the spines of rats and repair a skull defect in a monkey. The 3D printed material is strong, elastic, and capable of helping the body grow its own new bone to fix an injury.

Key features of the material include that it isn't brittle allowing the potential for surgeons to trim a piece to fit the patient without it crumbling. This is a common issue with other synthetic bone materials that are in testing and use. The researchers print the material from special printers at room temperature needing no heat or lasers unlike other materials.

Researcher Ramille Shah says that the team used a bioactive ceramic called hydroxyaptite commonly used as a material for attempting to regenerate bone. The team added a polymer called polycaprolactone to the hydroxyapatite and then used a solvent-based room temperature 3D printing technique using a unique combination of three solvents.

Shah says of the ink, "It doesn't dry out right away. It's a little wet which allows each layer to adhere to the previous one." The new substance is being called hyperelastic bone and the printer used to create the structure is the 3D-Bioplotter System by EnvisionTec. This printer is commercially available, but costs up to $300,000. The team says that in the animal experiments that have been conducted, blood vessels quickly moved into the porous fake bone material and that the implants weren't rejected by the immune systems of the animals. The hyperelastic bone material is expected to biodegrade over time as the body generates new bone and tissue to replace the synthetic material. The team hopes for human trials in the next five years.

SOURCE: Spectrum