Decellularized Rat Lung Extracellular Matrix as an In Vitro Platform for Canine Yolk Sac–Derived Endothelial Precursor Cells for Pulmonary Endothelium Reconstruction Studies

Pulmonary bioengineering holds significant promise for the development of functional lungs suitable for transplantation in patients with terminal lung diseases; however, it encounters considerable challenges. The inherent structural complexity, diverse cellular composition, and the intricate process of re-endothelialization the pulmonary vasculature complicate efforts to reconstruct viable lungs for transplantation. This study aimed to establish an innovative re-endothelialization technique utilizing decellularized scaffolds, integrating canine yolk sac-derived endothelial precursor cells with mechanical respiratory stimuli within a bioreactor framework. Wistar rat lungs were subjected to a decellularization protocol employing SDS + Triton X-100 0.5% and subsequently assessed for cytocompatibility with murine fibroblasts (3T3) and yolk sac (YS) cells in fragments. Following this, the recellularization of the whole-lung scaffold was evaluated under constant mechanical respiratory stimulation with YS cells. Each stage of the process was rigorously analyzed using histological staining, DAPI, scanning electron microscopy (SEM), and genomic DNA quantification. The findings reveal that the implemented alternating decellularization protocol resulted in a structured scaffold conducive to the culture of various cell types in fragments. When subjected to the complete scaffold recellularization model, the results indicated that YS cells are advantageous for the re-endothelialization process. Moreover, when employed in conjunction with the bioreactor model incorporating respiratory stimulation, these cells demonstrated enhanced cellular diffusion capacity and facilitated more homogeneous recellularization of the entire organ. These results signify a notable advancement in the reconstruction of new tissues for pulmonary transplantation.