Tissue engineering may have gotten closer to reality as a clinical solution, thanks to the recent work of biomedical researchers at the Royal Melbourne Institute of Technology (RMIT) in Australia. The research team developed a process for printing tiny, complex biomedical structures that could support the regrowth of new cells when implanted in damaged bone or cartilage. 

Regenerative medicine — currently used for mild to moderate injuries in orthopedic medicine — uses biological growth factors such as blood platelets and stem cells to stimulate natural tissue repair. With the correct support, regenerative treatments could address severely damaged or degenerated cartilage and bone, reducing the need for tissue grafts. 

Bioscaffolding provides space and support for healthy cell regrowth, but current 3D printing methods cannot create structures that are sufficiently small for some applications. The RMIT scaffolds could surpass existing technology by providing the best environment for cell growth. 

To overcome limitations in 3D printing minuscule structures, the researchers used the concept of negative space. By printing complex external molds and filling the tiny cavities with a biocompatible material, the research team created intricate structures they say are smaller than previous 3D printed scaffolds. The new scaffolds could eventually support flourishing cell regrowth as part of regenerative medicine procedures, such as stem cell therapy.

Such scaffolds created in the past have faced limitations due to the 3D printer’s ink nozzle size. The smallest of these used highly specialized materials, affecting cost and scalability. In contrast, the RMIT scaffolds can be printed with the most basic 3D printers using readily available medical-grade printing materials. 

The simplicity and affordability of the process allowed the researchers to print dozens of molds out of standard PVA glue. They then experimented with fillings made of biodegradable polymers, hydrogels, resins, and other biocompatible materials. Once hardened, the molds dissolve in water. The resulting scaffolds are about as wide as four human hairs and can support both bone and cartilage cells during regrowth.

Going forward, the team intends to test various scaffolds to determine the optimal design and materials to support cell regeneration. The researchers published their findings in the journal Advanced Materials Technologies.