To kick off National Science Week we’re checking in on some fascinating research on bone implants for cancer patients. Sometimes patients will have a bone or part of a bone removed to treat cancer, most commonly the jaw, the cranium, the hip bone, the femur and the tibia.
Thomas Nicolai is a researcher in the final year of his masters in biomedical technology in Marseille, in the South of France. He has crossed the globe to spend six months as an intern in the Department of Physics Research at Chris O`Brien Lifehouse.
Thomas was attracted by research being done at Lifehouse on 3D printing. We asked him what was involved: “We are trying to print a bone replacement for use after cancer surgery. Of course, we don’t actually print the bone. We print a scaffold on which we try and grow bone cells.”
Thomas explained the process: “We’ve done research and found a material with the best physical property for the scaffold. This material is called PEEK (poly ether ether ketone) but it needs extra help to get it into an ideal state. We treat it using a special technique called PI3 (plasma ion immersion implantation). This allows us to modify the properties of the PEEK so that it’s conducive to the growth of bone cells.”
The PI3 technique has been patented by Lifehouse collaborator University of Sydney Professor David McKenzie.
As a material, PEEK has similar properties to bone. However, PEEK has a very high melting point (343°C) so a special printer is needed to be able to 3D print it. The team is in discussions with a manufacturer in Canada to acquire one.
Another limitation in printing the scaffold is that it needs to form a matrix with interconnected holes. The holes need to be very fine and the team found that it wasn’t possible to achieve the correct resolution. They came up with a workaround.
“We print in layers and each layer has a grid. We rotate the printer slightly for each layer which creates a sort of crosshatch effect. This means that when we print the whole scaffold the holes are smaller giving a finer resolution. Improving the resolution to holes of around 300 micrometres gives us the perfect size for bone growth.”
“Then we add the bone cells with a cocktail of different molecules to help them grow and we are seeing bone grow. The idea is to cover the scaffold in bone growth and then implant it into a patient. However, we’re not there yet. We’re trying this in vitro and then we hope to move on to in vivo.”
Thomas is enjoying his time in Sydney and loves that he is meeting people from all over the world. Naturellement, there is one main thing he misses about France, the cheese.