RMIT Research Team Develops New Method for Designing Implants Using Bioprinting and Injection Molding

At the Royal Melbourne Institute of Technology (RMIT University), a team of researchers, along with doctors from St Vincent’s Hospital in Melbourne, have developed an innovative method for bioprinting medical implants. Instead of designing scaffolds on which cells will multiply, they 3D printed molds with cavities into which they injected biocompatible materials. Once the mold was dissolved in water, all that would remain would be this bio-scaffold. This technique, dubbed Negative Embodied Sacrificial Template 3D (NEST3D) should be compatible with a wide variety of materials but would especially allow the creation of microscopic structures.

In tissue engineering, the use of bioprinting is becoming more and more common as it can design of devices that promote the reconstruction of bones or muscles. Generally, 3D printed scaffolds are implanted in a patient’s body to encourage cells to reproduce and thus heal injuries which can range in severity. One of the obstacles that exists today is the size of these structures and their complexity: using scaffolds in the micron range remains complicated. Why not adopt a more indirect approach?

Using their method, researchers can design much more complex and smaller structures (photo credits: RMIT University)

This team of researchers decided to 3D print a mold with complex, intricately-patterned cavities. They were then able to inject biocompatible materials into these holes that form a welcoming scaffold for any cell. The researchers explain that they used a PVA glue to make the mold and injected biocompatible materials into it. Once hardened, the mold is immersed in water, which completely dissolves the glue. All that remains is the intricately shaped scaffold, as small as a fingernail.