ADPKD is genetically heterogeneous, dominated by two genes, PKD1 (located on chromosome 16.p13.3) affects ~78% of families and PKD2 (located on chromosome 4p21) affects ~15% of families. In 2016, a rare (affecting ~0.3% of families) third locus, the glucosidase II α subunit gene (on chromosome 11q12.3) was revealed (53). A study by Freedman et al (45) generated CRISPR-mutant kidney organoids from hPSCs and demonstrate that knocking out PKD1 or PKD2 induces cyst formation in kidney tubules. The subsequent study by Xu et al (54) reveals a distinct population of CD24⁺ renal epithelial cells with unique metabolic and gene regulatory programs and generates adult human kidney organoids from these cells. By combining CD24⁺ cell-derived tubule-like structures with multiplexed CRISPR-Cas9 gene editing, an ADPKD organoid model that enables rapid cyst induction was established, highlighting the potential of lineage-specific differentiation strategies for improved disease modeling (54).

Building on this foundation, a study by Vishy et al (55) develops base-edited PKD kidney organoids that have four clinical non-sense mutations in PKD1 and PKD2, which enables allele-specific modeling of cystogenesis and therapeutic testing. A key finding is that heterozygous mutated organoids do not spontaneously form cysts, suggesting a potential therapeutic window for intervention. Furthermore, from a translational perspective, the study by Vishy et al (55) identifies eukaryotic ribosome-selective glycosides as candidate therapeutics, demonstrating that these compounds are able to mediate non-sense mutation readthrough, which is potentially a targeted treatment strategy for patients with such mutations.

ARPKD is a kidney disease that differs from ADPKD. Although both disorders are classified as ciliopathies, sharing core pathological pathways such as ciliary dysfunction and abnormal epithelial cell proliferation, ARPKD has unique clinical and genetic characteristics (56). It has an autosomal recessive inheritance pattern, primarily caused by mutations in the polycystic kidney and hepatic disease 1 (PKHD1) gene (and less commonly in the DAZ-interacting zinc finger protein 1-like gene) (57,58), with the onset of the disorder typically occurring in neonates or childhood. The hallmark features of ARPKD, namely fusiform dilatation of the renal CDs accompanied by congenital hepatic fibrosis (59,60), differ to the widespread cyst formation that occurs throughout the kidneys and adult-onset presentation that are characteristic of ADPKD.

A study by Low et al (46) established an ARPKD model using patient-derived iPSCs harboring biallelic PKHD1 frameshift mutations. The aforementioned study demonstrates that cAMP activation via the natural compound forskolin induces extensive cystogenesis specifically in the PKHD1^-/- organoids, a response that is markedly attenuated in heterozygous and wild-type controls (46). Furthermore, a study by Hiratsuka et al (61) integrates ARPKD organoids with an organ-on-chip platform. This revealed a novel pathogenic mechanism, demonstrating that fluid flow-induced mechanical stress, mediated by the mechanosensors Ras-related C3 botulinum toxin substrate 1 (RAC1) and Fos proto-oncogene (c-Fos), promotes cyst formation (61).

The original animal model of FD, developed in a study by Ohshima et al (62), used a targeting construct to knock out the α-galactosidase A (α-Gal A) gene in C57BL/6 male mice, which were then mated with normal C57BL/6 females to obtain heterozygous mice lacking the α-Gal A gene, generating α-Gal A^+/- mice. The construction of the animal model was completed by mating α-Gal A^+/- female mice with C57BL/6 male mice to obtain α-Gal A^-/0 mutant male mice (62).

Several years later, a study by Porto et al (63) carried out pharmacological investigations using fibroblasts from patients with FD. After the study by Freedman et al (45) that first applied CRISPR/Cas9 gene editing technology to kidney organoid disease models, several studies have applied CRISPR/Cas9 or related genome-editing approaches to kidney organoid models by disrupting, introducing or correcting disease-associated genes (45,54,55,64-68). A 2021 study by Kim et al (69) confirmed that, in kidney organoids derived from hiPSCs carrying mutations in GLA, the gene encoding α-Gal A, the deposition of the glycosphingolipid globotriaosylceramide (Gb3) led to structural deformation of podocytes and renal tubular cells, thereby exacerbating oxidative stress and apoptosis. The aforementioned study further evaluates two therapeutic strategies, namely enzyme replacement therapy (using recombinant human α-Gal A), which is shown to alleviate oxidative stress and repair cell structure by eliminating Gb3, and antioxidant therapy (glutathione replacement), which is shown to directly reduce oxidative stress, thereby alleviating structural damage to organoids (69).

A study by Cui et al (65) differentiated FD model kidney organoids using patient-derived and gene-edited hiPSCs. Kidney organoids were cultivated from hiPSCs of two male patients with different types of GLA mutations who had FD. Compared with the wild-type organoids, the patient-derived organoids had decreased α-Gal A activity and increased Gb3 lipid deposition. These abnormalities were more pronounced in organoids carrying the classic Fabry disease-associated GLA mutation, which was associated with markedly reduced α-Gal A activity and a more severe Gb3 accumulation phenotype. Using electron microscopy, multilamellar lysosomal inclusion bodies, also known as zebra bodies, were observed in the mutant organoids, thereby reproducing a characteristic pathological feature of Fabry nephropathy.

To further investigate treatment strategies, CRISPR/Cas9 was used to knock out the α-1,4-galactosyltransferase (A4GALT) gene, which encodes Gb3 synthase. The results demonstrate that, in the GLA mutant kidney organoids, A4GALT knockout reduces Gb3 deposition, and lysosome inclusion bodies are not observed (64).

Collectively, these findings not only confirm the potential of glutathione and A4GALT as possible new therapeutic targets for FD, but they also provide a reliable in vitro model platform for drug development (64).

KIN is an extremely rare hereditary form of chronic interstitial nephritis. Although a reliable population-based incidence rate has not been established, its estimated prevalence is <1 per 1,000,000 individuals, it accounts for <1% of kidney biopsies, and <100 native-kidney cases have been reported in the literature (70,71). In order to identify the causative gene for nephronophthisis (NPHP)-like ciliopathy, a study by Zhou et al (72) evaluates two affected siblings of Maori descent in New Zealand. Renal histopathology analysis reveals enlarged nuclei (nucleolar enlargement) in the renal cells, and a diagnosis of KIN is suggested. Subsequent pure-synteny localization and exome sequencing reveals a pure-synteny non-sense mutation in FAN1, the gene that encodes Fanconi anemia-associated nuclease 1. Additionally, through sequencing FAN1 exons from the DNA samples of 10 families with KIN, it is revealed that a recessive mutation in FAN1 is the important etiologic factor in KIN. Another study by Lim et al (73) generated kidney organoids using FAN1-mutant and wild-type hiPSCs. After inducing DNA damage via mitomycin C treatment, the FAN1-mutant organoids demonstrated increased expression of the DNA damage-associated marker H2A.X compared with their wild-type counterparts; Ki67 was also assessed to evaluate cell proliferation and viability within the organoids. Taken together, these findings demonstrate that FAN1-deficient kidney organoids successfully recapitulate the KIN phenotype, suggesting a potential model platform for investigating the mechanisms through which defective DNA repair contributes to the development of CKD.

GS (online mendelian inheritance in man: 263800), also known as familial hypokalemia-hypomagnesemia, is a salt-losing tubulopathy that is characterized by hypomagnesiuria, hypocalciuria and secondary aldosteronism, leading to hypokalemia and metabolic alkalosis with autosomal recessive inheritance (74). GS is associated with mutations in the solute carrier family 12 member 3 (SLC12A3) gene, which encodes the thiazide-sensitive sodium chloride cotransporter (NCCT) in the distal convoluted tubule (75). A study by Lim et al (66) prepared general hiPSCs and gene-modified hiPSCs by sequencing the SLC12A3 gene using CRISPR/Cas9 technology with peripheral blood mononuclear cells from patients with GS. Furthermore, in a subsequent study (68), the SLC12A3 gene mutation was corrected using CRISPR-Cas9 technology, yielding genetically repaired hiPSCs. When both the mutant and corrected hiPSCs are differentiated into kidney organoids, the SLC12A3-mutant tissues exhibit reduced mRNA and protein levels of NCCT compared with wild-type controls. However, these levels are restored in the genetically corrected organoids. Although the aforementioned study models GS in kidney organoids for the first time and demonstrates reduced NCCT expression levels in E-cadherin-positive epithelial cells, as well as its rescue by genetic correction, it did not directly demonstrate the defective electrolyte transport associated with disease pathogenesis. Overcoming this limitation may require more advanced kidney organoid platforms that incorporate vascularization, tubular fluid flow and functional assays capable of assessing solute transport.

AS is a one of the most common hereditary glomerular diseases. Its main clinical features include progressive glomerular injury and extrarenal manifestations, particularly sensorineural hearing loss and ocular abnormalities and it may eventually progress to end-stage renal disease (76). The causative genes for AS are COL4A3-5, which encode the α3, α4 and α5 chains of type IV collagen, respectively. Mutations in these genes lead to abnormal type IV collagen structure in the glomerular basement membrane (BM) (77-79). Given the severity of the condition and the current lack of curative options, developing a preclinical platform that accurately recapitulates the disease phenotype is challenging.

Using kidney organoids derived from hiPSCs, studies have successfully constructed disease models that simulate AS (80,81). A study by Hirayama et al (80) reports on hiPSCs derived from two male patients with AS and differentiates them into kidney organoids. The organoids derived from these patients successfully reproduces the key disease phenotypes, including abnormal expression of the type IV collagen α5 chain, α5(IV). The aforementioned study confirms that the severity of the phenotype is associated with the type of genetic mutation, and that the normal expression of α5 (IV) can be restored through genetic correction. Furthermore, the chemical chaperone 4-phenylbutyric acid improves BM defects in mild-phenotype organoids, although it is ineffective in severe-phenotype organoids. These findings suggest the necessity of personalized treatment based on genetic typing (80).

A study by Morais et al (81) reports the BM pathology in AS. It is revealed that, although kidney organoids derived from iPS cells from patients with AS form normal-appearing glomeruli and tubules under a light microscope, their molecular composition is already abnormal, manifesting as an increased deposition of laminin β2, specifically in the extraglomerular BM. Furthermore, the aforementioned study reveals that BM composition is regulated from development to adulthood, a process that is disrupted by pathogenic COL4A5 variants. Consequently, the model successfully recapitulates the laminin dysregulation in patients with AS, suggesting that kidney organoids may serve as a potential platform for studying aberrant BM assembly in human developmental diseases (81).

The normal function of glomerular podocytes relies on the slit diaphragm, a protein complex composed of molecules including nephrin (NPHS1) and podocin (NPHS2). Mutations in either NPHS1 or 2 disrupt the formation of the slit diaphragm, leading to congenital nephrotic syndrome (82,83). Several studies validate this pathogenic mechanism using patient-specific iPSC-derived kidney organoid models (84-87). Two studies demonstrate that a NPHS1 missense mutation results in abnormal NPHS1 localization and impairs slit diaphragm formation in podocytes (84,85). However, a study by Jansen et al (86) reports that NPHS2 mutations lead to both a loss of NPHS2 expression levels and the mislocalization of NPHS1, which is a reversible phenotype upon genetic correction. Furthermore, a study by Majmundar et al (87) models glomerular developmental abnormalities and an increased rate of apoptosis by introducing a patient-derived nitric oxide synthase 1 adaptor protein variant into human kidney organoids. Collectively, the aforementioned studies highlight the possible utility of kidney organoids in terms of recapitulating the pathological mechanisms of podocytopathies.

ADTKD, the third most common monogenic kidney disease, causes progressive renal failure via tubular/interstitial injury, and it is attributed to mutations in five genes, namely uromodulin, mucin 1 (MUC1), renin (REN), SEC61 translocon subunit α 1 and hepatocyte nuclear factor 1-β (HNF1β) (88,89).

Kidney organoid models provide a platform for investigating the functional roles of causative genes in ADTKD. A study by Przepiorski et al (68), which investigates the role of the HNF1β gene, uses CRISPR/Cas9 technology to knock out HNF1β in order to observe any downregulation in the expression of markers associated with proximal tubules and thick ascending limbs in the organoids. This demonstrates the regulatory role of genes in nephron segment patterning. Another study by Mae et al (90) investigates UB organoids, further revealing that the heterozygous loss of HNF1β leads to impaired branching morphogenesis and loss of apicobasal polarity. By contrast, a study by Dvela-Levitt et al (91) generates kidney organoids from iPSCs derived from patients with MUC1 mutations. This recapitulates the pathological hallmark of aberrant mutant protein accumulation, and use this model to identify a small-molecule compound, BRD4780, which directs the mutant protein for degradation via the lysosomal pathway, demonstrating the application of organoids in targeted drug discovery (91).

AR-RTD is a lethal genetic disorder characterized by the complete absence or severe hypoplasia of proximal tubules, which results from pathogenic mutations in key genes of the renin-angiotensin-aldosterone system (RAAS), including angiotensin-converting enzyme (ACE), angiotensin II receptor type 1 (AGTR1), autophagy-related and REN (92). A study by Pode-Shakked et al (93) generated RAAS-deficient kidney organoids by differentiating ACE^-/- and AGTR1^-/- iPSCs, as well as patient-derived iPSCs with AR-RTD, into kidney organoids. This demonstrates that RAAS-deficient organoids form proximal tubules in vitro; however, AGTR1^-/- organoids display impaired engraftment at the renal vesicle stage due to insufficient VEGF-A expression levels, suggesting that delayed angiogenesis is a possible mechanism that underlies autosomal recessive renal tubular dysgenesis (93) Additionally, the aforementioned study reveals that, under conventional or hypoxic culture conditions, the loss of RAAS genes does not directly affect proximal tubule patterning in organoids. Following transplantation under the renal capsule of immunodeficient mice, renal vesicle-stage AGTR1^-/- organoids have impaired engraftment due to insufficient VEGF-A expression levels and delayed angiogenesis. Hypoxic culture induces the expression of VEGF-A and rescues the engraftment of AGTR1^-/- organoids (93). These findings suggest that proximal tubule dysgenesis in AR-RTD is not primarily induced by cell-autonomous tubular defects, but is induced by delayed angiogenesis as a non-cell-autonomous consequence of impaired RAAS signaling.

NPHP is an autosomal recessive disorder that is characterized pathologically by disruption of the tubular BM, tubular atrophy, interstitial fibrosis and progression to end-stage kidney disease (94). To investigate its underlying mechanisms, studies focus on the intraflagellar transport 140 (IFT140) gene, which encodes a core component of the intraflagellar transport complex A involved in retrograde ciliary transport (95,96). In a study by Forbes et al (51), kidney organoids are generated using patient-derived IFT140-mutant iPSCs alongside isogenic gene-corrected control iPSCs. This reveals that mutant organoids have shortened, malformed primary cilia and defects in cellular polarization, whereas genetic correction successfully rescues these abnormal phenotypes, confirming the central role of IFT140 mutations in NPHP pathogenesis (51).

Cystinosis is an autosomal recessive lysosomal storage disorder caused by mutations in the cystinosin, lysosomal cystine transporter gene, which encodes the protein cystinosin (97). The major characteristic of cystinosis is the accumulation of cystine in lysosomes, which leads to progressive renal tubular damage and multiple organ dysfunction (98).

A study by Hollywood et al (98) differentiates kidney organoids from iPSCs derived from patients with cystinosis, recapitulating key disease phenotypes. For example, cystine crystal accumulation was observed in the proximal tubular cells of the organoids, accompanied by lysosomal dysfunction, elevated oxidative stress and impaired levels of autophagy. Electron microscopy and molecular analyses further revealed features of mitochondrial dysfunction and increased rates of apoptosis of renal tubular epithelial cells in the organoids, demonstrating the successful modeling of progressive injury processes observed in patient kidneys (98) (Table II).

Kidney organoid technology demonstrates multifaceted application potential, including disease modeling, toxicological safety assessment, personalized medicine, organ transplantation, organ-on-chip development and extracellular vesicle (EV)-associated research (99).

Two transplantation models promote vascularization and maturation of kidney organoids. A study by van den Berg et al (48) first transplanted organoids under the renal capsule of immunodeficient mice,. Subsequently, a study by Koning et al (100) used intracoelomic transplantation into chicken embryos to study vasculogenesis in kidney organoids. These transplantation studies demonstrated that in vivo engraftment promotes the vascularization and maturation of kidney organoids. In the renal subcapsular transplantation model, van den Berg et al (48) showed that transplanted organoids developed host-derived vascularization, fenestrated endothelial cells and podocyte foot processes, and exhibited selective permeability to dextran and albumin, suggesting the formation of a functional glomerular filtration barrier. In the intracoelomic transplantation model, Koning et al (100) demonstrated vascular integration and improved maturation of kidney organoids in the chicken embryo environment. Together, these findings indicate that transplantation can enhance vascularization, glomerular maturation and epithelial organization in kidney organoids.

The study by Lim et al (101) was the first to combine collagen scaffold encapsulation with minimally invasive intrarenal injection, overcoming the shortcomings of traditional subcapsular or abdominal transplantation that require surgical exposure. Furthermore, the method avoids the problems of uneven distribution and low survival rate that occurs with simple cell injection. This study (101) demonstrates that this method not only preserves the structural integrity of organoids, but it also promotes their functional integration into the host kidney, providing a feasible preclinical model for future organoid-based kidney regeneration therapy.

Microfluidic technology, via the construction of microphysiological systems with dynamic fluidic microenvironments, provides kidney organoids with a culture platform that more closely mimics in vivo conditions, notably enhancing organoid vascularization, maturation and functional simulation capabilities. This technology is able to simulate fluid shear stress and intraluminal pressure within nephrons, promoting the polarization and functional maturation of renal tubular epithelial cells (102). Through multi-chamber designs, it enables spatial coupling of the glomerular filtration barrier with tubular structures, simulating the urine-formation process (103). Additionally, in disease modeling, microfluidic systems successfully recapitulate drug-induced nephrotoxicity (104) and the cyst-expansion mechanisms in genetic diseases such as ADPKD (105). In drug screening, its integrated high-throughput detection systems allow real-time monitoring of organoid responses to drugs, which notably improves the precision of nephrotoxicity assessments (106). Furthermore, connecting kidney organoid chips with other organ chips provides a novel platform for studying systemic diseases and multi-organ interactions (107). However, despite their advantages, current microfluidic platforms have several technical bottlenecks that limit their broader application, including: i) Chip material (polydimethylsiloxane) adsorption of hydrophobic drugs causing dosing inaccuracy; ii) inconsistent flow shear stress across replicates due to bubble formation; iii) limited imaging depth (typically <200 µm) for thick organoids; and iv) a lack of standardized protocols for organoid loading and perfusion. Moreover, common failure points involve organoid detachment, leakage at chip interfaces and microbial contamination during long-term culture (>7 days). Therefore, these issues must be addressed prior to the widespread adoption of this technology.

EVs are heterogeneous membrane-enclosed nanoparticles that mediate intercellular communication and participate in both physiological and pathophysiological conditions in the kidney (108). EVs derived from stem cells, especially MSCs, which are adult stem cells found in tissues such as bone marrow, adipose tissue, umbilical cord, placenta and dental pulp, have demonstrated notable regenerative potential in various models of acute and chronic kidney injury (109,110).

Kidney organoids have notably revolutionized renal research and, when combined with gene-editing techniques, are a valuable research model. This model uses genome-wide screening to investigate the underlying mechanisms of genetic diseases, facilitates drug and toxicity screening on personalized human-derived platforms, and serves as a key tool for deciphering renal morphogenesis and functional maintenance (111,112). However, several constraints limit clinical translation. Compared with conventional animal models, kidney organoids provide a human genetic background and greater compatibility with high-throughput screening. However, they lack key aspects of systemic physiology, including hemodynamic forces, endocrine regulation and immune interactions (111,112) For drug screening, organoids enable rapid phenotypic readouts such as cyst growth and protein mislocalization, but have lower scalability compared with 2D cultures. Reproducibility remains a major concern. Independent differentiations of the same hiPSC line yield organoids with up to 30-40% variability in nephron progenitor numbers (44). In addition, scalability for drug screening is limited by manual handling; bioreactor-based expansion does improve yield, although this process also introduces shear stress artifacts.

Firstly, the cells generated by kidney organoids are mostly immature, possessing embryonic or fetal characteristics, and fail to form the mature cell types that are unique to adult kidneys (112,113). The epithelial cells within organoids primarily express development-associated genes and often show limited expression or maturation of functional proteins associated with kidney diseases, such as NPHS1, NPHS2, COL4A3-5, SLC12A3 and uromodulin. Targeted induction protocols are required to promote the further maturation of organoids, which enables the construction of a research model that more closely mimics the physiological characteristics of adult kidneys (44).

Secondly, batch-to-batch variations, residual off-target cells and individual variability during maturation can lead to misleading conclusions when comparing patient-derived organoids with isogenic control organoids (44,114). This heterogeneity notably undermines the reliability of research results and presents a critical factor limiting their precise application.

Thirdly, key cell types, such as vascular endothelial cells and immune cells, are absent in kidney organoids derived from hPSCs; however, these cells perform crucial roles in the maintenance of renal physiological functions and pathological processes (for example, inflammation and injury repair) (114-116). This deficiency has notable limitations for investigations into the interactions between renal cells and immune cells, which especially hinders the in vitro modeling of complex diseases such as infectious and autoimmune nephropathies (114,116).

Fourthly, kidney organoids lack the macroanatomical structures that are similar to those of natural kidneys and more complex organ tissue architectures. This prevents them from simulating core renal functions, such as tubular reabsorption and renal filtration (114), making it difficult to recapitulate the physiological functional characteristics of adult kidneys.

The functional validation of kidney organoids has been insufficiently addressed in numerous studies (44,111-113,116,117). Beyond morphological assessment, critical parameters also require systematic evaluation. Electrophysiological properties, including transepithelial resistance and ion channel activity, remain largely uncharacterized. Electrolyte transport could be measured via an assessment of Na⁺/K⁺-ATPase activity (namely, ouabain-sensitive ATP hydrolysis) (117) and by evaluating glucose uptake or reabsorption (105). Vascularization could be assessed morphologically by calculating the CD31⁺ vascular area fraction and functionally by evaluating fluorescent tracer perfusion. Transcriptomic maturity should be benchmarked using principal component analysis, comparing organoid transcriptomes to both fetal (12-20 weeks) and adult kidney reference datasets; a maturity score closer to that of the adult kidney indicates an improved differentiation (44). Long-term stability over weeks to months in culture or after transplantation also requires systematic reporting. These functional benchmarks are essential for validating organoid utility in disease modeling and drug screening (Table III).

Organoids-on-chip are able to optimize nutrient exchange via shear stress, and compared with static culture, they are more likely to induce organoids to form structures resembling mature kidneys (102,118). This technology has a wide range of applications, for example, it can be used to study vascularization (providing key support for drug testing), and can simulate glomerular filtration function through the co-culture of podocytes and endothelial cells (103,104).

Although organoids-on-chip offer notable advantages over traditional research platforms, they are still not able to fully replicate the physiological complexity of human kidneys and currently face several challenges, including limited standardization, poor reproducibility, chip material-related limitations and microfluidic designs that may not fully accommodate the size, 3D architecture and long-term perfusion requirements of kidney organoids. These limitations complicate organoid integration, stable perfusion, long-term culture and imaging-based analysis at different tissue depths (119).

As a cutting-edge technology, 3D bioprinting has a potential for developing kidney organoids. Through enabling the precise positioning of cells and biomaterials, 3D bioprinting may construct larger-scale, more complex kidney-like tissues, suggesting a potential for the development of preclinical models (120). A key advantage of this method is its capacity for high-throughput production, which ensures consistent cell numbers, high viability and reduced inter-organoid variability (121). By leveraging iPSCs, bioprinting platforms have been demonstrated to generate kidney constructs with improved uniformity and expression of lineage-specific markers, including NPHS1, NPHS2 and WT1 for podocytes; LTL, E-cadherin and AQP1 for tubular epithelial cells; and CD31/PECAM1 and VE-cadherin/CDH5 for endothelial cells (122). Furthermore, the technology allows the modulation of biophysical parameters, such as cell number and tissue size, to improve the modelling of renal functional and physiological characteristics (121). This strategy not only mitigates patient-derived heterogeneity, but it also establishes stable, reproducible models that are suitable for high-throughput screening and comparative studies (118).

The integration of patient-derived iPSCs, genome editing, reporter lines, microfluidic devices and 3D bioengineering approaches is expanding the utility of kidney organoids for disease modeling and preclinical drug evaluation (107,111-114,117-124). Reporter lines can facilitate lineage tracing, cell-type identification and real-time monitoring of organoid differentiation; examples include SIX2-based reporters for nephron progenitor cells, WT1- or NPHS1-based reporters for podocyte-lineage cells, and PECAM1/CD31- or CDH5-based reporters for endothelial cells. In parallel, patient-derived iPSCs and gene-edited isogenic controls allow disease-associated phenotypes to be modeled in a human genetic background, whereas microfluidic and bioengineering platforms can provide dynamic culture conditions and more standardized tissue construction (107,111-114,117-124). Together, these approaches may improve the analysis of pathological endpoints related to drug efficacy and toxicity and support more individualized disease modeling.

Translating kidney organoids to clinical applications requires overcoming several hurdles. Good Manufacturing Practice compliance demands xeno-free, defined media and stringent quality control release criteria. Regulatory barriers are substantial, since guidance from the Food and Drug Administration on organoid-based products remains in its early phase. Furthermore, scalability is limited by manual handling; in addition, although bioreactor-based expansion improves yield, it also introduces shear stress artifacts. Quantitative benchmarking is suggested to be mandated for preclinical studies. Proposed metrics include organoid size distribution (target coefficient of variation <20%), cell type proportions by single-cell RNA-sequencing (>80% kidney lineage) and functional assays, such as FITC-inulin clearance for glomerular filtration or Na⁺/K⁺-ATPase activity for proximal tubule function. These benchmarks may facilitate cross-laboratory comparisons and accelerate clinical translation.

As well as hereditary disorders, kidney organoids are also applied to model viral nephropathies. SARS-CoV-2 infection of kidney organoids recapitulates viral entry, replication and cytopathic effects, primarily targeting proximal tubular cells via ACE2, with enhanced organoid maturation improving viral replication modeling (123). Similarly, BK polyomavirus, a major cause of nephropathy in transplant recipients, induces nuclear enlargement characteristic of BK virus nephropathy in kidney tubuloids, and such models enable antiviral compound testing (124). These applications expand the use of kidney organoids beyond genetic disorders, highlighting their potential in infectious disease modeling and drug development.