3D Bioprinted Renal Constructs Using Kidney-Specific ECM Bioink System on Kidney Regeneration.

The final stage of chronic kidney disease (CKD) remains an irreversible condition, with dialysis and transplantation as the only treatment options. Recently, 3D bioprinting has emerged as a promising strategy for bioengineering renal constructs capable of restoring damaged kidney. A critical challenge in this approach is the development of a kidney-specific bioink that provides an optimal biochemical and biomechanical microenvironment to support renal cell organization, maturation, and functional restoration. In this study, a kidney-derived decellularized extracellular matrix bioink (kdECMMA) to facilitate renal tissue bioprinting is utilized. The kdECMMA bioink exhibits excellent printability, structural integrity, and biological characteristics. Human kidney cells encapsulated within the bioprinted kdECMMA constructs demonstrate high viability and progressive maturation over time. To evaluate its in vivo feasibility, bioprinted renal constructs into the kidneys of nude rats are implanted. After 1 and 2 months, the implanted constructs display newly formed glomerular- and tubular-like structures, with human-specific markers confirming the integration of human cells within these formations. Particularly, renal tissue formation is also observed in cell-free kdECMMA constructs, suggesting the recruitment of host renal progenitor cells into the implantation site. These findings highlight the potential of kdECMMA bioinks in creating a kidney-specific microenvironment conducive to renal regeneration.