It’s not uncommon for people to break or lose their bones due to accidents or diseases like bone cancer. As treatment, doctors implant bone grafts, or bits of bone tissue from a donor. Held in place with wires and screws, they help the body regenerate healthy bone.
Unfortunately, this process has some evident flaws. First, the bone graft must be cut to fit precisely where the old bone used to be. Second, if metal plates or scaffolding are inserted during surgery, they usually have to be surgically removed. Lastly, for those missing a large amount of bone, such as in an arm or leg, often the only option is to amputate the limb.
3D printed bones could change all of that by making the process more natural and convenient for the patient. Doctors would no longer have to take a bone graft from another bone or search for a bone donor. They could simply scan the area and model the structure of the new bone.
Every implant looks different and can be shaped precisely to the patient’s bone. Speed of production is also important when looking to save a limb, which makes 3D printing the perfect candidate technology.
Once 3D printed, a bone can then be implanted into a patient. Ideally, the bone graft will dissolve as new bone grows, reducing the need for more surgery.
Although such bones can be printed using compounds similar to natural bone, researchers are also looking into printing bones in other materials with special properties.
Based in Europe, Xilloc specializes in producing patient-specific implants, including 3D printed bone. Based on a CT scan of the patient, engineers design the implants so that they fit perfectly in place.
Each implant is printed in calcium phosphate, a main compound in natural bone. As a result, it will eventually merge with and become part of the patient’s existing bone.
Some 3D printed bones require sintering (think SLS 3D printing) in order to increase their strength. However, the extreme temperatures tend to cause some warping. CT-Bone doesn’t require this treatment, so implants can be produced with high precision.
The process is still in testing and isn’t yet available, but it shows great potential. The pre-clinical study showed that, within 24 weeks, the implant fused with the patient’s bone. Later analysis revealed that bone tissue and even bone marrow were beginning to form in the transplant.
Material scientists at Northwestern University, IL, developed a new 3D printable material dubbed “hyperelastic bone” (HB). This flexible material is interesting because it can be cut, rolled, and easily worked with. As a result, the material is very easy to implant during surgery.
HB is composed of over 90% hydroxyapatite, which is a major compound lending rigidity to real bone. Combined with a special polymer, this brittle material becomes a flexible but consistent substance. It acts as a scaffold, encouraging the growth of blood vessels and cells with its porosity and absorbance.
The material is promising because it could be a cheap solution to the bone transplant problem. It’s affordable to manufacture, can be 3D printed at room temperature, and stores for up to a year. Hospitals in developing countries, for example, could make use of the material without needing an expensive refrigeration system.
Again, human trials haven’t been conducted yet. But when tested with both mammalian and human stem cells, the material facilitated promising cell and bone growth.
In fact, HB (3D printer not included) is commercially available. It can be purchased through Allevi, a bioprinting company that specializes in biological applications. So, what are you waiting for?
Scientists at New York University are also developing their own 3D printed bones. Their goal is to help those in need, such as children with skull deformations or veterans who require bone scaffolding.
Instead of flexibility, the scientists focused on optimized healing by mimicking bone shape and composition. The bones are 3D printed layer by layer in beta-tricalcium phosphate and then superheated to their final ceramic state.
A special coating of dipyridamole is added to the 3D printed bone. This speeds up new bone formation and attracts bone stem cells. As the printed bone is resorbed, this coating is gradually released.
So far, initial tests have been very promising. After 6 months, 77% of the scaffolding was absorbed by the mammal’s body, and the newly grown bone was just as strong as the original.
Do 3D printed bones sound exciting to you? Try checking out these related articles:
License: The text of "3D Printed Bones – 3 Most Promising Projects of 2018" by All3DP is licensed under a Creative Commons Attribution 4.0 International License.
Subscribe to updates from All3DP
You are subscribed to updates from All3DP
You can’t subscribe to updates from All3DP. Learn more…