Organ transplant waiting lists in the U.S. are long, with some patients waiting years for a suitable organ, while others may not survive the wait due to rejection risks. To address this issue, researchers in regenerative medicine are exploring ways to use a patient's own cells to produce personalized organs like hearts, kidneys, and livers on demand.

Ensuring that newly grown organs receive adequate oxygen and nutrients is a challenge. Researchers at Stanford have developed tools to design and 3D print intricate vascular networks necessary for organ blood circulation. Their platform, published in Science, creates designs resembling human body vasculature faster than previous methods, translating them into 3D printer instructions.

Organ-scale vasculature

When blood reaches an organ, it flows from large arteries into smaller branching blood vessels, allowing nutrient exchange with surrounding tissues. In metabolically demanding organs like the heart, cells need to be very close to blood vessels to survive. The complexity of vascular networks varies among organs, making it challenging to model realistic blood vessel architectures efficiently.

Marsden and her team developed an algorithm to create vascular trees mimicking native organ blood vessel structures. They incorporated fluid dynamics simulations to ensure even blood distribution and reduce network generation time. The model achieved a high vessel density, keeping cells close to blood vessels, a task that was previously time-consuming.

A bioprinted heart

While the printed vascular networks are not functional blood vessels yet, they are a step towards creating complex vascular systems. Researchers aim to develop physiological vessels that include muscle cells, endothelial cells, and other components necessary for functionality. They are also exploring methods to stimulate the growth of tiny blood vessels that are too small to print.

Skylar-Scott and his team are working on bioprinting a fully functional human heart by integrating heart cells from human stem cells with a complex vascular network. This critical step in the process involves designing a vascular tree to support cell growth and nourishment at an organ scale.

Overall, this research is a significant advancement in bioprinting technology, paving the way for creating personalized organs that could revolutionize the field of regenerative medicine.

Source: News-Medical

Source: News-Medical