Conventional kidney replacement therapies, such as dialysis and transplantation, sustain life but do not restore full renal physiology. Emerging technologies now aim to replicate key nephron-level functions using modular, biologically or bioengineered systems. Rather than reconstructing the entire kidney, these approaches focus on restoring discrete physiological roles, such as filtration, reabsorption, and endocrine signaling, through stem cell–based constructs, implantable devices, and biofabricated tissues. In this review, we introduce a function-based, modular framework for evaluating nephron replacement strategies. We assess four major platforms: kidney organoids, implantable bioartificial kidneys, three-dimensional bioprinted renal tissues, and decellularized kidney scaffolds. Each is examined in terms of its ability to replicate specific nephron functions, its degree of segmental specialization, and its readiness for clinical integration. Although no single approach currently achieves full nephron functionality or systemic integration, the modular combination of complementary systems may offer a scalable path toward next-generation kidney support. The review highlights recent advances, persistent challenges, and the potential for hybrid therapies that bridge biological realism with engineering precision. Ethical and regulatory considerations are also discussed to support responsible translation.
Stepanova et al. (Mon,) studied this question.