Research Progress and Critical Challenges of Bioartificial Kidneys in Renal Replacement Therapy for End-Stage Renal Disease.

Chronic kidney disease (CKD), one of the major global public health burdens, continues to exhibit a rising prevalence worldwide. The growing population of patients with end-stage renal disease (ESRD) has led to an increasing demand for renal replacement therapy (RRT). Although dialysis effectively prolongs survival, it fails to fully replicate kidney function. In addition, the persistent shortage of donor kidneys results in prolonged waiting periods for kidney transplantation. Emerging renal replacement strategies, such as kidney organoids, have demonstrated considerable potential. However, multiple technical limitations continue to hinder their near-term clinical translation. Bioartificial kidneys (BAKs), which integrate engineering and biological technologies, generally consist of artificial filtration membranes and living-cell bioreactors designed to mimic native kidney function. Advances in nanotechnology, biomaterials, and tissue engineering have accelerated the development of implantable bioartificial kidneys (iBAKs), making them an important research direction in renal replacement therapy. These innovations have improved membrane performance, biocompatibility, and cellular integration; however, substantial challenges remain regarding long-term stability, immune compatibility, and clinical validation before translation into human applications. Specifically, limited cell sources and uncertain long-term biocompatibility remain major barriers to iBAK development. In the future, biosensors and artificial intelligence (AI) technologies may be incorporated into bioartificial kidneys to enable personalized precision therapy. This review focuses on the developmental and major challenges of bioartificial kidneys, with detailed discussion of recent progress in implantable artificial kidneys.