Conducted by Birmingham and Warwick universities, the work describes how the bioinks – which are being commercialised under the tradename 4Degra - slowly degrade in the body over about a year, allowing mature healing to take place over time. According to the researchers, scaffolds created using the inks have several advantages over existing approaches used to fill soft tissue voids following trauma or surgery. These include better elasticity to conform to irregular spaces and undergo compression, compatibility with tissues, and non-toxic biodegradation. The study is published in Nature Communications.
"3D printed materials have received a lot of attention in the tissue engineering world,” said research lead Professor Andrew Dove, from the University of Birmingham's School of Chemistry. “However void-filling materials to provide mechanical support, biocompatibility, and surface erosion characteristics that ensure consistent tissue support during the healing process, and this means a fourth dimension (time) needs to be considered in material design.
"We have demonstrated that it's possible to produce highly porous scaffolds with shape memory, and our processes and materials will enable production of self-fitting scaffolds that take on soft tissue void geometry in a minimally invasive surgery without deforming or applying pressure to the surrounding tissues. Over time, the scaffold erodes with minimal swelling, allowing slow continuous tissue infiltration without mechanical degradation."
The research paper describes several compositions of 4Degra bioinks, meaning the material can be tweaked to provide different levels of mechanical strength depending on the needs of individual medical cases. All of the compositions include a photoinitiator and a photoinhibitor to ensure the resins rapidly turn into gel on exposure to light, which enables a range of different scaffold shapes to be created.
Lab tests showed that the scaffold degrades by surface erosion into non-acidic products, allowing for slow, continuous tissue regeneration. A mouse model with a scaffold implant was found to have 80 per cent of the structure remaining after four months, indicating that the scaffolds should remain in place for at least a year.
4D Biomaterials, the spinout company seeking to commercialise the research, is now offering the 4Degra bioink to 3D printing companies and medical device manufacturers, and is seeking to scale up production.
"We are looking to collaborate with innovative companies in Europe and North America to develop a new generation of 3D-printed medical devices that translate the unique advantages of the 4Degra resin-ink platform into improved treatment outcomes for patients,” said CEO Phil Smith.