3D Printing Enables Complex Vascular Networks for Prosthetic Applications

Computational models enabling the swift design of vascular networks for 3D-printed organs could advance the prospect of artificial liver, kidney, or heart transplants, eliminating the dependency on donors.

Individuals suffering from organ failure often require transplants. Merely 10% of the global transplant demand is currently met. In response, researchers are innovating techniques to produce lab-grown organs via 3D printing. However, these efforts hinge on experimental methodologies for sustaining the vascular networks long enough to remain viable for days or weeks.

To tackle this issue, Allison Marsden from Stanford University and her team have developed a computational model that facilitates the design of these networks for any organ using mathematical principles explaining how blood vessels branch within the body.

They evaluated their method by creating a network of 25 vessels with 1 cm wide ring-shaped structures that were 3D printed from kidney cells according to their design.

The team then fabricated the vascular network into rings using cold gelatin particles, subsequently heated to 37°C (98.6°F) to dissolve the gelatin, resulting in a network of hollow channels measuring 1 mm in width that mirrored blood vessels. The researchers continued to circulate oxygen and nutrient solutions through the channels to replicate normal blood flow.

After one week, the ring contained approximately 400 times more viable cells compared to a similar ring made from bloodless kidney cells that had been exposed to blood-like fluids.

“We succeeded in keeping the cells near the network alive,” remarks Marsden. “However, the more distant cells perished because we were unable to print the smaller, more intricately branched networks necessary to deliver nutrients to those regions. Our team is actively seeking solutions to this challenge.”

“They are definitely pushing the limits of feasibility,” states Hugues Talbot from University Paris-Clay, France. This novel approach might someday enable scientists to design vascular networks for full-sized organs in mere hours, rather than days or weeks. “Networks designed in this manner could potentially substitute or at least complement lab-grown organs in the future.”

First, researchers must devise methods for 3D printing these vascular networks onto larger organs. If progress continues on this path, Marsden expresses a desire to experiment with 3D-printed organs in pigs within the next five years.