Chinese scientists successfully tested biodegradable 3D printed artificial bone on rabbits
- April 1, 2015
Medical applications of 3D printing technology have been widely successful in recent months. While most bioprinting innovations will still take a few years to be implemented, 3D printed titanium implants have already been used to save lives in academic hospitals throughout the world. But now the Xi’an Particle Cloud Advanced Materials Technology company from China has successfully combined 3D bioprinting with implant applications. In collaboration with doctors from the military Xijing hospital in Xi’an, they have 3D printed an orthopaedic bone for a rabbit using a 3D bioprinter.
As scientists explained, bone defects caused by severe trauma or even tumors create very complicated challenges for orthopaedic doctors. There are currently, in short, no safe and effective treatment methods, though 3D printing technology could provide the answer. Developing identical biomimetic artificial bone structures, that share all the physical and chemical characteristics of bone could provide a simple solution through transplantation.
And that is exactly what this team of Chiense scientists have been working on the past five years. They have developed a 3D printer capable of bioprinting artificial bones complete with the pore structures and mechanical strength you find on regular bones, that are even biocompatible as well. The first tests on animals have also proved to be widely successful; just a few days ago, a rabbit received an implanted femoral condyle in the fourth military medical university in the Xijing hospital in Xi’an. The bioprinted bone is expected to function exactly like any other in the rabbit’s body.
But perhaps most impressive about this bioprinting innovation is the entirely new 3D printing technique it relies on. It’s called Filament Free Printing (or FFP), and it slightly resembles FDM 3D printing techniques but instead tackles some of the common problems associated with that technology. Specifically, FDM technology is limited by the technical limitations that filament plastics force onto it, such as high costs, unnecessary waste and the inability to create accurate mixtures of materials.
FFP 3D printing avoids these problems by directly extrudes polymer or ceramic particles at a very high precision, instead of first melting filament into printable paste. These particles can be extruded with or without a prior heating stage, and are otherwise extruded in the exact same way as FDM printing methods in a layer-upon-layer fashion. ‘This method gives the user a wide range of options in terms of printing material. Composite materials are easily made, used and accurately recreated, creating a far wider range of applications,’ its developers write. Slicing and extrusion in and XYZ pattern are otherwise exactly similar.
This technological innovation is thus effectively allowing scientists to extrude bio materials using relatively inexpensive FDM 3D printing technology but then without the need to first make filament. To 3D print bone structures, mixtures of inorganic materials present in human bones (such as Hydroxyapatite, a natural form of calcium) can simply be mixed with collagen particles. A mixture of these two materials (in a 1:1 mixture) can subsequently be mixed with 5-fold deionized water to become an extrudable ceramic slurry. When heated in an extrusion head, it's a perfect ‘filament’ for 3D printing natural bone structures.
As initial animal tests using this FFP 3D printing technique were so successful, it’s expected that similar 3D bioprinted implants can be made for humans with segmental bone defects in the near future. It looks like actual bioprinting applications are just around the corner after all.
ECC "Sokolniki", pavilion 2, 5-iy Luchevoy prosek, 7/1