Purpose: Of the over 100,000 patients on the organ transplant waiting list, 85% are waiting for a kidney, but only 27% of these patients will receive an organ. Addressing this large clinical need, perfusion decellularization and recellularization can be used to engineer fully transplantable bioengineered kidneys. A decellularization process removes the native cells from a porcine kidney while leaving behind a matrix that preserves the natural kidney architecture. The matrix is then recellularized with human cells to restore kidney function. Here, a process is described in which primary cells obtained from a non-transplanted human kidney are used to create multiple viable bioengineered kidneys.
Methods: In collaboration with OPO partners, human kidneys are received that were not accepted for transplant. Using an enzymatic perfusion protocol, donated kidneys are digested, and then with selective straining and sieving, whole glomeruli and renal tubule cells are isolated. These isolated glomeruli and renal tubule cells are separately plated on tissue culture flasks to allow the distinct cell populations to proliferate. After the proliferation period, these cell populations are characterized and cryopreserved separately. Importantly, cryopreservation allows for the ability to expand and seed the cells into multiple bioengineered kidneys on demand. Multiple primary cell populations are seeded into a decellularized porcine matrix to produce a bioengineered kidney. Bioengineered kidneys are cultured for up to 28 days prior to functional assessment.
Results: Through the primary cell isolation culture and cell expansion, this procedure has the capacity to produce enough donor cells to create more than 6 bioengineered kidneys per donated kidney. At the end of the production processes, bioengineered kidneys are assessed for functional capabilities via both benchtop and implant assessment. When perfused with whole blood for 120 minutes, bioengineered kidneys are able to filter blood and produce urine.
Conclusions: Approximately 3,500 kidneys are not accepted for transplant each year. Here, we demonstrate a process to use donated kidneys to create bioengineered kidneys that have the potential to improve quality and duration of life for thousands of patients with chronic kidney disease. Furthermore, through this process, bioengineered kidneys could be made available on demand rather than waiting the average 3-5 years for a donated kidney allograft.