Researchers recently focused in on a new combination of 3D-printed microfiber scaffolding and hydrogels, with the goal of restoring cartilage, according to a news release from Tenische Universität München (TUM).
The release reports that the composites tested by the researchers indicated elasticity and stiffness comparable to knee-joint tissue, as well as the ability to support the growth and cross-linking of human cartilage cells.
The researchers note that they expect the new research to have an impact on other areas of soft-tissue engineering research, including breast reconstruction and heart tissue engineering.
The international study appears in the journal Nature Communications
Playing a key role during the research, the release says, was a new 3D printing technique called melt electrospinning writing, which simultaneously provides room for cell growth as well as the necessary mechanical stiffness.
Dietmar W. Hutmacher, PhD, professor and one of the lead authors, explains that the method offers much more freedom in the design of the 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 soft gel—proteoglycans or, in our case, a biocamptible hydrogel—with a network of very thin fibers,” Hutmacher says in the release.
The release adds that scaffolding filaments produced by melt electrospinning writing can be as thin as 5 micrometers in diameter, reportedly a 20-fold improvement over conventional methods.
Hutmacher is based at the Queensland University of Technology in Australia and is a Hans Fischer Senior Fellow of the TUM Institute for Advanced Study. His TUM-IAS Group on Regenerative Medicine is hosted by TUM professor Dr Arndt Schilling, head of the Research Department of Plastic Surgery and Hand Surgery at TUM’s university hospital Klinkum rechts der Isar.
The release says the collaborators—working in Australia, Germany, the Netherlands, and the UK—brought a wide range of research tools to conduct the investigation. Efforts targeting the design, fabrication, and mechanical testing of hydrogel-fiber 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, the release states.
After validating the computer model of their hydrogel-fiber composites, the researchers say they are using it to assess a range of potential applications.
“The new approach looks promising not only for joint repair, but also for uses such as breast reconstruction following a post-tumor mastectomy or heart tissue engineering. We need to implant the scaffolding under the muscle, and fiber-reinforced hydrogel could prove critical in regenerating large volumes of breast tissue, as well as the biomechanically highly loaded heart valves,” Hutmacher notes.
The release says that Hutmacher and his collaborators at TUM, which include professor Schilling, PD Dr Jan-Thorsten Schantz, and Dr Elizabeth Balmayor, already plan to use the approach described in the Nature Communications paper for their breast tissue engineering research. Additionally, they have begun a project in collaboration with the group of professor Stefan Jockenhövel and Dr Petula Mela at the RWTH Aachen, centered on engineering heart valve tissue.
[Photo caption: Confocal laser microscopy of scaffold populated with human mesenchymal precursor cells]
[Photo Credit: D. Hutmacher/QUT]