Combination of Bioprinting Methods to create Functional Blood Vessels

Researchers at UMC Utrecht have succeeded for the first time in combining volumetric bioprinting with melt electroprinting. This combines the speed and cell-friendliness of volumetric printing with the structural strength needed to create functional blood vessels.

Melt electroprinting, a precision 3D printing process, offers excellent mechanical durability. But direct printing of cells in scaffolds is impossible due to high temperatures. That’s where volumetric bioprinting comes in to introduce cell-laden gels into the scaffolds.

The process begins with the creation of a cylindrical scaffold by melt electroprinting. Then, the scaffold is dipped in a light-sensitive gel and positioned in the volumetric bioprinter. The printer’s laser selectively solidifies the gel.

“To ensure accuracy, we meticulously positioned the scaffold at the center of the vial,” Größbacher explained. “Any deviation from the center would result in an offset volumetric print. However, we successfully achieved perfect alignment by printing the scaffold on a mandrel specially designed to fit the vial.”

The team conducted experiments with different scaffold thicknesses and investigated different positions for the bioprinted gels. Two differently labeled stem cells were used to bioprint a prototype blood vessel.

In addition, the researchers designed bioprinted vessels with side holes to allow permeability. They also produced more complex structures, including bifurcated vessels and vessels with functional venous valves.

Größbacher stated, “This study served as a proof of principle. Our next objective is to substitute the stem cells with functional cells that constitute an actual blood vessel, including the inclusion of muscle cells and fibrous tissue surrounding the epithelial cells. Our current aim is to bioprint a fully functional blood vessel.”

Find out more about UMC Utrecht at umcutrecht.nl.