Assessing the Live Decellularized Renal Microvasculature Post-Transplantation using Intravital Microscopy

Transplantation is the ideal solution for end-stage renal failure, but the growing mismatch between organ supply and demand accentuates the need for alternative solutions like the bioartificial kidney. Several approaches to developing this technology have been demonstrated, and whole organ decellularization appears to be a promising methodology. One major challenge to this strategy is maintaining vascular integrity and functionality post-transplantation. Most models to examine the microvasculature have primarily utilized in vitro or in vivo techniques that are incapable of providing adequate spatial and temporal resolution. Here, we show that decellularized scaffolds orthotopically transplanted into rats initially retain microvascular structure in vivo using intravital two-photon microscopy, as previously identified in vitro. Large molecular weight dextran molecules also provide real-time evidence of the onset of ischemia and increases in microvascular permeability, support substantial translocation of dextran macromolecules from glomerular and peritubular capillary tracks as early as 12 hours after transplantation. Macromolecular extravasation continued across a week, at which time the decellularized microarchitecture was significantly compromised. These results indicate that a in vivo method capable of tracking microvascular integrity represents a powerful interdisciplinary approach for studying scaffold viability and identifying ways to promote scaffold longevity and angiogenesis in bioartificial organs.