Urine-derived stem cells in kidney disease: progress, challenges, and future directions

• Urine-derived stem cells (USCs) are a non-invasive, accessible source of multipotent cells with therapeutic potential for kidney disease. • USCs exhibit paracrine activity, immunomodulation, and efficient extracellular vesicle production, contributing to anti-fibrotic and pro-regenerative effects. • Recent advances in biomaterials and delivery technologies, such as scaffold-free cell sheets and engineered EVs, enhance the translational potential of USC-based therapies. • Key challenges including functional integration, delivery optimization, and donor variability must be addressed to facilitate clinical translation.