The Future for End-Stage Kidney Disease Treatment: Implantable Bioartificial Kidney Challenge

Despite limited organ availability and post-transplant complications, kidney transplantation remains the optimal treatment for End-Stage Kidney Disease (ESKD). However, innovative dialysis technologies such as portable, wearable, and implantable bioartificial kidney systems are being developed with the aim of addressing these issues and improving patient care. An ideal implantable device could combine bioreactors and blood ultrafiltration to replicate key native cell functions for solute reabsorption, secretion, and endocrinologic activities. Today, the feasibility of an implantable bioreactor for renal cell therapy opens the challenge of developing a fully implantable bioartificial kidney based on silicon nanopore membranes to ensure immunological isolation, cell viability, and the possibility of maintaining a blood substrate for metabolic activities. Current technology is not sufficient to obtain an efficient artificial bioreactor to reach physiological blood purification, which requires a more complex system to produce an ultrafiltrate from the blood that can be processed by cells and eliminated as urine. The number of cells in the bioreactor, endocrine activity, immunological cell isolation, solute and fluid secretion/reabsorption, cell viability, blood and ultrafiltration flow control, and thrombogenicity are fundamental issues that require a new technology that today appears to be a challenge for the design of an implantable artificial kidney. This review aims to analyze the state of the art in this particular field of kidney replacement therapy to highlight the current limitations and possible future technology developments to create implanted and wearable organs capable of treating ESKD with artificial organs that can replicate all native kidneys functions.