Researchers print salt template for bone implants

Material researchers from the Swiss Federal Institute of Technology in Zurich (ETH) have developed a new process for producing bone implants. Made from salt and magnesium, they used a 3D printer to produce stable and bioresorbable scaffolds with regularly structured pores.

According to an ETH Zurich press release, implants made from magnesium, a light metal, have the advantage that they can biodegrade in the body, which absorbs magnesium as a mineral nutrient. This makes it unnecessary to have a second surgery to remove the implant, which is the case for implants made with traditional materials like titanium.

“The possibility to control the pore size, distribution and orientation in the material is decisive for clinical success, because bone cells like to grow into these pores,” said ETH Professor of Metal Physics and Technology Jörg Löffler. This in turn promotes rapid healing.  

Because standard table salt is not suitable for printing, the researchers developed a gel-like salt paste. They then printed a 3D salt template, which they subsequently sintered to give it sufficient mechanical strength. In a next step, they infiltrated the pores with magnesium melt. After mechanical shaping, the researchers dissolved the salt, leaving a pure magnesium implant with structured porosity.

The researchers’ development is the subject of a forthcoming article in the journal Advanced Materials. The idea for this new manufacturing procedure came from work conducted by Nicole Kleger within the framework of her Master’s thesis at ETH Zurich, where she is now a doctoral student.