The potential of 3D ice printing for artificial blood vessels

The organ transplant crisis in the United States has reached a critical point, with over 100,000 individuals on the waiting list and approximately 6,000 patients losing their lives annually due to the scarcity of available organs. This dire need for organs, including hearts, kidneys, and livers, significantly overshadows the supply, leaving many in a prolonged, often fatal wait. In response to this growing issue, tissue engineering, specifically the development of lab-grown organs and tissues, emerges as a beacon of hope aimed at bridging the gap between demand and supply.

A pivotal challenge in the realm of tissue engineering is the creation of intricate blood vessel networks that mirror the functionality and design of natural ones. The traditional methodologies for crafting artificial blood vessels have fallen short, lacking the complexity and efficiency required for integration into the human body. Yet, a study presented by Feimo Yang, a graduate student at Carnegie Mellon University, alongside Philip LeDuc and Burak Ozdoganlar, introduces a novel approach that may well pave the way for significant advancements in this field.

Their research, unveiled at the 68th Biophysical Society Annual Meeting in Philadelphia, Pennsylvania, explores the use of 3D ice printing as a method for constructing blood vessel structures that bear a striking resemblance to their natural counterparts. This innovative technique leverages a stream of water on an ultra-cold surface, manipulating the freezing process to maintain a liquid phase atop the forming ice. This freeform process eliminates the layering effect common in traditional 3D printing, resulting in smoother structures.

3D printed ice template of blood vessels shown on the left. The right shows imaging of cells forming a blood vessel-like structure on the template one week later. Image courtesy of Feimo Yang.

A unique aspect of their method is the use of heavy water, wherein hydrogen atoms are replaced by deuterium, thereby elevating the freezing point of the water, and facilitating the creation of these smooth structures. Upon embedding these ice templates within a gelatinous material known as GelMA and exposing it to UV light, the gelatine hardens and the ice melts away, revealing realistic channels akin to blood vessels.

The team has achieved promising results, successfully introducing endothelial cells into these fabricated vessels where they remained viable for up to two weeks, with aspirations to extend this duration in future experiments. This breakthrough not only holds immense potential for organ transplants but also offers novel avenues for drug testing and personalised medicine. By coating these vessels with a patient's own cells, it becomes possible to observe cellular responses to drug treatments before administration, providing a more tailored and potentially safer therapeutic approach.

The advent of 3D ice printing in the creation of blood vessel networks represents a significant stride towards solving the organ transplant crisis. Through replicating the intricate structures of natural blood vessels, this technology stands at the forefront of tissue engineering, heralding a new era of medical innovation and hope for thousands awaiting life-saving transplants.