Vascularized nerve grafts (VNG) may offer an advantage in peripheral nerve regeneration by avoiding ischemic damage and central necrosis observed in non-VNG, particularly for the treatment of large and long nerve defects. However, surgical complexity, donor site morbidity and limited nerve availability remain important drawbacks for the clinical use of VNG. Here we explore the potential of perfusion-decellularization for bioengineering a VNG to be used in peripheral nerve reconstruction.
Porcine sciatic nerves were surgically procured along with their vascular pedicle attached. The specimens were decellularized via perfusion-decellularization and preservation of the extracellular matrix (ECM), vascular patency and tissue cytokine contents were examined. Scaffold reendothelialization was conducted with porcine aortic endothelial cells in a perfusion-bioreactor.
Morphologic examination of decellularized VNG and analysis of the DNA content demonstrated cell clearance whereas ECM content and structures of the nerve fascicles were preserved. Using 3D micro-computed tomography imaging we observed optimal vasculature preservation in decellularized scaffolds, down to the capillary level. Cytokine quantification demonstrated measurable levels of growth factors after decellularization. Endothelial cell engraftment of the large caliber vessels was observed in reendothelialized scaffolds.
In this study we provide evidence that perfusion-decellularization can be used to create vascularized nerve scaffolds in which the vasculature and the ECM component are well preserved. As compared to non-vascularized conduits, engineered vascularized nerve scaffolds may represent an ideal approach for promoting better nerve regeneration in larger nerve defect reconstructions.