3D-Bioprinting has shown promise not only to rebuild organs, but for producing experimental tissues for drug trials and laboratory testing. This technique uses a patient's own cells bioprinted in the form of a tissues. Given its inherently interdisciplinary nature, 3D-Bioprinting is accelerating at an ever increasing rate.
Now a similar bioprinting technique has been developed to produce artificial bone. A team at Swansea Universities Welsh Centre for Printing and Coating have developed the technique in hopes of producing an effective means toward printing transplantable bone tissue.
There is clearly a demand for this technology, given that almost 600,000 bone-graft procedures were performed in the United States and Canada last year. These are currently performed with synthetic cement-based materials and also with a patient's own bone. Surgeons are seeking new ways to repair the damage while working with a limited range of materials.
Bioprinting of trabecular bone tissue and the resulting matrix structure produced.
The Swansea team have developed a technique that uses 3D bioprinting technology to deposit an artificial bone matrix into the exact shape of a bone. These engineered structures can facilitate the regeneration of bone tissue by providing a structure for osteocyte cells to attach themselves to, and an environment for new tissue to form.
Previously limitations in bone materials have meant that the structures do not have appropriate mechanical integrity or allow the formation of new tissue. Additionally, it has been difficult to replicate the naturally occurring bone-cartilage interface.
Micrograph of a hollow bioprinted channel for nerves to grow through.
The Swansea team determined that a useful aspect of bioprinting is that it can produce the exact shape of a structure, with a biocompatible material that is both durable and regenerative. This composite is made from a combination of gelatine, agarose, collagen alginate, calcium phosphate and poly-capro-lactone.
The artificial bioprinted bones are capable of fusing with a patient's natural bones over time with no envisaged complications. The team is applying for regulatory approval of its process so they can make this technology commercially available by early 2016. If successful, the technology would offer an alternative to conventional surgical bone grafts.
Micrographs of the surface of the bone material showing the smooth geometrical structure generated.
As with conventional 3D Printing, bioprinting offers the opportunity to create the exact shape of the bone in deposited layers until the bone is fully formed. The concept is that the artificial bone produced using this process can be transplanted into the body, where the structure will form a scaffold that will be replaced by living bone over a period of four-six months.
Currently, it takes under two hours to print a small bone structure with trabecular features, indicating that the fabrication could take place within the operating theatre. Subsequently, ensuring that the bone composite material is deposited with the correct viscosity ensures that a smooth surface structure is produced with no stress raising features.
In the future, bioprinted bones could be produced with enough fidelity to underpin complex spinal reconstruction. Additionally, the bone material can be further modified with a collagen coating to enhance its compatibility with cartilage cells. Studies of these bones have shown that it promotes the proliferation of stem cells and offers promise for greatly enhancing the treatment of a wide variety of orthopedic defects. Although this technology is not hugely revolutionary, it does demonstrate that the flexibility of this family of bioprinting technologies has the potential to help improve lives.
For further information please visit: www.creationengineering.co.uk/biomedical-technology.html
Applications for this technology:
- To produce patient specific bone to replace or repair damaged or diseased tissues.
- Improved bone-cartilage interface over existing scaffold designs.
- Improved mechanical integrity, achieving a compressive strength of 80MPa ±5%.
- The deposition materials can be biologically modified to promote stem cell proliferation.