Much research has focused on hydrogels, polymer-based materials containing large amounts of water, but hydrogels with both self-healing and complex construction have proved elusive until now.
Hydrogels need to fulfil two key criteria if they are to be effective replacements for organic tissue: the ability to form extremely complex shapes, and to self-heal after sustaining damage. Previously, hydrogels created in the laboratory had either the capability of being 3D printed into complex shapes, or had the ability to self-heal. This research realises the first time these two capabilities had been combined into one material.
The development of these materials may now be easier, and cheaper, thanks to the use of 3D printing: the researchers in the MP4MNT (Materials and Processing for Micro and Nanotechnologies) team of the Department of Applied Science and Technology of the Politecnico di Torino, coordinated by Professor Fabrizio Pirri. The researchers detailed their work in the prestigious journal Nature Communications.
In addition, the hydrogel was created using both commercially available materials and printer, thus making the approach proposed extremely flexible and potentially applicable anywhere, throwing open the door for development in the fields of both biomedicine and soft robotics.
The research was carried out in the context of the HYDROPRINT3D doctoral project, funded by the Compagnia di San Paolo, in the frame of “Joint Research Projects with Top Universities” initiative, by the PhD student Matteo Caprioli, under the supervision of the DISAT researcher Ignazio Roppolo, in collaboration with Professor Magdassi’s research group of the Hebrew University of Jerusalem (Israel).
The researchers used the digital pulsed light to create a semi-interpenetrated structure of polymer strands that, when severed, could rejoin in 12 hours at room temperature with no outside intervention. The restored section retains 72% of its initial strength.
“[For] many years, in the MP4MNT group, a research unit coordinated by Dr Annalisa Chiappone and I, specifically devoted to development of new materials that can be processed using 3D printing activated by light,” said Ignazio Roppolo, Researcher, DISAT. “3D printing is able to offer a synergistic effect between the design of the object and the intrinsic properties of materials, making [it] possible to obtain manufactured items with unique features.
“From our perspective, we need to take advantage of this synergy to best develop the capabilities of 3D printing, so that this can truly become an element of our everyday life. And this research falls right in line with this philosophy.”
This research represents a first step towards the development of highly complex devices, which can exploit both the complex geometries and the intrinsic self-healing properties in various application fields. Once biocompatibility studies have been refined, it will be possible to use these structures both for cellular mechanism research and for regenerative medicine applications.
Source: News-Medical.Net
Journal reference: Caprioli, M., et al. (2021) 3D-printed self-healing hydrogels via Digital Light Processing. Nature Communications. doi.org/10.1038/s41467-021-22802-z.
