New 3D printing technique is used to create joint cartilage
16 May 2015
An new study, published in the journal, Nature Communications, points the way toward wider, more effective use of bio-compatible materials in repairing human tissues.
Focusing on the difficult case of restoring cartilage, which requires both flexibility and mechanical strength, the international team of researchers investigated a new combination of 3D printed micro-fibre scaffolding and hydrogels.
The composites they tested showed elasticity and stiffness comparable to knee-joint tissue, as well as the ability to support the growth and cross-linking of human cartilage cells. Researchers at the Technische Universität München (TUM) expect the new approach to have an impact on other areas of soft-tissue engineering research, including breast reconstruction and heart tissue engineering.
A new 3D printing technique called melt electrospinning writing played a key role, simultaneously providing room for cell growth as well as the needed mechanical stiffness. This method offers much more freedom in the design of scaffolding to promote healing and growth of new tissue.
"It allows us to more closely imitate nature's way of building joint cartilage, which means reinforcing a soft gel – proteoglycans or, in our case, a biocompatible hydrogel – with a network of very thin fibers," says Professor Dietmar Hutmacher, one of the lead authors of the Nature Communications article, now based at the Queensland University of Technology in Australia.
Scaffolding filaments produced by melt electrospinning writing can be as thin as five micrometres in diameter, a 20-fold improvement over conventional methods.
The collaborators – working in Australia, Germany, the Netherlands, and the UK – brought a wide range of research tools to bear on this investigation. Efforts focusing on the design, fabrication, and mechanical testing of hydrogel-fibre composites were complemented by comparisons with equine knee-joint cartilage, experiments with the growth of human cartilage cells in the artificial matrix, and computational simulations.
Having validated the computer model of their hydrogel-fibre composites, the researchers are using it to assess a variety of potential applications, including breast reconstruction following a post-tumour mastectomy or heart tissue engineering.