BRISTOL, England, June 23 (UPI) -- A newly developed bio-ink has allowed researchers at Bristol University to engineer 3D-printed tissue. The technology could eventually enable the printing of complex tissues for surgical implants -- like cartilage and bone for knee and hip replacements.
Bio-ink is a material that can serve as scaffolding onto which scientists can implant and grow stem cells -- cells that can differentiate into any other type of cell.
Researchers created the new bio-ink using two polymers. A natural polymer extracted from seaweed serves as the scaffolding, while a synthetic polymer, commonly used in the medical field, triggers a phase change in the scaffolding, from liquid to solid, when the temperature is raised.
"Designing the new bio-ink was extremely challenging. You need a material that is printable, strong enough to maintain its shape when immersed in nutrients, and that is not harmful to the cells," lead researcher Adam Perriman, from the School of Cellular and Molecular Medicine, said in a news release. "We managed to do this, but there was a lot of trial and error before we cracked the final formulation."
Researchers retrofitted a benchtop 3D printer to turn their bio-ink into scaffolding. As the liquid is deposited by the printer, it's heated and turns to gel, creating the support system needed to grow cell cultures.
The scientists were able to successfully embed stem cells and differentiate them into osteoblasts and chondrocytes, cells that secrete bone tissue and cartilage, respectively.
"What was really astonishing for us was when the cell nutrients were introduced, the synthetic polymer was completely expelled from the 3D structure, leaving only the stem cells and the natural seaweed polymer," Perriman said. "This, in turn, created microscopic pores in the structure, which provided more effective nutrient access for the stem cells."
The new research was recently published in the journal Advanced Healthcare Materials.
