3D Bioprinting: Advances in Printing Functional Blood Vessels in the Laboratory

Picture: CIC biomaGUNE

The replication of human tissue in the laboratory has posed major challenges for biomedical research for decades. Animal models often provide results that are only partially transferable, while two-dimensional cell cultures fail to capture the complexity of organ structures. Advances in 3D printing are now opening up new perspectives. A research team at the Spanish center CIC biomaGUNE is developing methods to print blood vessels with multilayered structures and functional properties.

The Hybrid Biofunctional Materials group, led by Ikerbasque researcher Dorleta Jimenez de Aberasturi, combines modern bioprinting technologies with nanostructured materials. The goal is to create vascular models that not only consist of multiple layers but can also respond to external stimuli.

A key aspect is the choice of biomaterials. Methacrylated gelatin, a modified, light-curable gel, serves as the base material. It is cell-compatible, and its viscosity can be adjusted. This is complemented by components of the extracellular matrix derived from animal tissue. To mimic the mechanical stress experienced by blood vessels, the researchers integrated gold nanoparticles. These strongly react to laser light and enable the simulation of a pulsating blood flow.

“The type of mechanical forces to which blood vessels are subjected due to changes in blood pressure is something important but difficult to recreate. These changes are important if we want to obtain realistic responses in the cells,” explained Dr Jimenez de Aberasturi, lead researcher at the laboratory.

Together with partners from Maastricht University and Utrecht University, the team used different printing methods. In embedded bioprinting, soft or liquid materials are printed into a carrier medium, allowing for the creation of structures that would otherwise collapse in air. Using volumetric bioprinting, they were also able to produce vascular models with functional valves by curing an entire volume simultaneously.

“By combining these improved materials and various printing techniques, we managed to produce more complex structures that are much more similar to those found in the human body,” they said. However, they stressed that “this is a very complex process. Although we are now very close to making these arteries very real, there are still steps to be taken. And every step is a world unto itself”.

The results demonstrate that complex structures such as arteries or veins can increasingly be produced in a realistic manner. For clinical applications, however, the road ahead remains long, the researchers stress. Still, the developed models could already make an important contribution to disease research and drug testing today.