Bioengineered Vessel Grafts: From Table to Patient
In today’s scientific community there is a major quest to find new ways to create bioengineered organs and vessels. Not only does the problem of creating effective vessels persist, the creation of adaptable vessels that grow along with the patient is also extremely relevant. A major drawback of the bioengineered vessels created in the past is that they have not been able to grow within child patients, causing a greater need for future invasive, dangerous, and costly surgeries.
However, the University of Minnesota has recently taken major steps within the scientific community to find a remedy to this salient dilemma. Professor Robert Tranquillo and his colleagues from the University of Minnesota have harvested post- natal sheep-skin cells and used these to create vessel grafts. The methods for creating these grafts were surprisingly uncomplicated. The sheep cells were combined with fibrin, a gelatin-like substance, to create tubes in the shape of vessels. Then, a bioreactor previously created in the lab was used to pump necessary nutrients to keep the cells alive and promote cell growth within the vessel. Detergents were then used to remove the sheep cells from the graft, leaving behind a vessel capable of being implanted into non-sheep bodies. The benefits to this step are monumental: patients receiving the vessel grafts will not need to adapt to the donor cells used to create the grafts and it will allow the regeneration of the vessels with the patients’ cells instead.
The implications of this impressive tactic was later observed when the first vessel grafts were implanted into three, five month-old lambs to replace their pulmonary artery. The scientists of the University of Minnesota observed that not only did the lambs’ own cells colonize within the vessel, but the vessel’s shape was internally bent to adapt to their bodies. Even more remarkable: as the lambs grew in size, their implanted vessel also grew. After 45 weeks, the graft’s diameter had increased by 56% and the quantity of blood able to pump through the graft had increased by an astonishing 216%. Furthermore, collagen within the vessel had increased by 465%, symbolizing that the graft had actually grown within the body.
The significance of this study is towering: human-created vessels have the ability to function and adapt within the body of a living organism. This could make heart surgery procedures less complicated and more efficient. The next step for these researchers is to gain approval from the Food and Drug Administration (FDA) to implement these vessels into human bodies, a task that will be greatly deliberated and prepared for, but crucial for the advancement and integrity of the project.