The Self-Regulating Bioartificial Kidney, Part 2: Managing the Challenges
The Kidney Project was launched in 2015 by William Fissell, MD, and Shuvo Roy, PhD, with the goal “to create a small, surgically implanted, and free-standing bioartificial kidney to treat end stage renal disease.” Building on previous research and work by Dr. Fissell, Dr. Roy and David Humes, MD, the Kidney Project has resulted in a bioartificial kidney that is moving from porcine to human trials. Although the Kidney Project and its technology are still at an early stage of development, if all goes according to plan, final clinical trials of the bioartificial kidney and FDA approval may be possible within the early part of the next decade. (Read about the anatomy of the bioartificial kidney in Part 1 of this blog series.)
The Kidney Project has experienced a variety of challenges in refining the bioartificial kidney. For years the inability to sufficiently miniaturize the device for implantation in the abdominal cavity was an obstacle to designing a successful prototype. Yet this resolved itself as the silicon manufacturing industry continued to make smaller and smaller chips, allowing the device to be downsized to workable dimensions.
Clotting risks presented another challenge. The innately irregular, pulsatile flow of blood could readily lead to turbulence in the device’s looping tubes. To address this, Vanderbilt bioengineer Amanda Buck employed principles of fluid dynamics to ensure the smooth flow of blood to and from the device. The team used 3D printing to produce multiple refinements of these silicone channel models before achieving optimal flow characteristics.
Interestingly, because the technology used to develop the device mitigates the possibility of rejection, the list of adverse effects is expected to be no greater than those present with other implantable devices—i.e., possible surgical trauma, scars and infections.
While 9,000 people are on the waitlist pending FDA approval, trials will proceed with caution— and small numbers. Up to 10 initial participants will receive an implant for one month to test the hemofilter and assure there are no clotting issues. After that hurdle is cleared, the filtering process will be evaluated. Only then will Dr. Fissell and Dr. Roy’s team add the live cell component, thereby testing the complete device.
Ample room for optimism
Artificial organs are not new, of course. In fact, the total artificial heart was conceived almost 60 years ago. Since then, other artificial organs have also been developed. There are bio-hybrid devices that simulate livers, which serve to keep patients with acute liver failure alive while awaiting transplant. And BIOLIFE4D is working on a bioprinted heart, grown on a 3D dissolvable scaffold. The patient’s own cells will be grafted onto the scaffold and cultured in a bioreactor, forming a complete heart ready for transplantation.
Despite all of these advancements, artificial organs are still a bridge to transplant, not a permanent solution. To date, there are no artificial, biohybrid or bioreactor-grown organs that have successfully replaced a natural organ over a normal life expectancy. If The Kidney Project succeeds, their device will be a first for patients.