Lund University researchers have designed a new bioink which allows small human-sized airways to be 3D-bioprinted with the help of patient cells. The 3D-printed constructs are biocompatible and support new blood vessel growth into the transplanted material. This could be an important milestone in 3D-printing organs.
The study was published in Advanced Materials.
This work could be impactful because there are not enough donor lungs to meet clinical demand.
Therefore, researchers are looking at ways to increase the number of lungs available for transplantation. One approach is fabricating lungs in the lab by combining cells with a bioengineered scaffold.
"We started small by fabricating small tubes, because this is a feature found in both airways and in the vasculature of the lung. By using our new bioink with stem cells isolated from patient airways, we were able to bioprint small airways which had multiple layers of cells and remained open over time," said Darcy Wagner, Associate Professor and senior author of the study.
The researchers first designed a new bioink (a printable material with cells) for 3D-bioprinting human tissue. The bioink was made by combining two materials: a material derived from seaweed, alginate, and extracellular matrix derived from lung tissue.
This new bioink supports the bioprinted material over several stages of its development towards tissue. They then used the bioink to 3D-bioprint small human airways containing two types of cells found in human airways. However, this bioink can be adapted for any tissue or organ type.
The team used a mouse model closely resembling the immunosuppression used in patients undergoing organ transplantation. When transplanted, they found that 3D-printed constructs made from the new bioink were well-tolerated and supported new blood vessels.