Aim: Tissue-specific extracellular matrix promotes tissue regeneration and repair. We aimed to identify the optimal decellularized matrices for tissue-engineered vascular graft (TEVG).
Methods: Decellularized aorta of fetal pigs (DAFP, n = 6, group A), decellularized aorta of adult pigs (DAAP, n = 6, group B), and decellularized carotid artery of adult pigs (DCAP, n = 6, group C) were prepared. Scaffolds were compared using histology and ultrastructure. Endothelial cell (EC) and myofibroblast (MFB) infiltration assessments were performed in vitro. Cell infiltration was measured in vivo. Biomechanical properties were also determined.
Results: Almost original cells were removed by the acellularization procedure, while the construction of the matrix basically remained. In vitro, monolayer ECs and multi-layer MFBs were formed onto the internal surface of the specimens after 3 weeks. In vivo, cell infiltration in group A significantly increased at the 6th and 8th week when compared with groups B and C (p < 0.01). The infiltrated cells were mainly MFBs and a few CD4+ T-lymphocytes/macrophages in the specimens. Groups A and B showed greater axial compliance than group C (p < 0.01).
Conclusion: DAFP was the most suitable for use as a small-caliber vascular graft.
Keywords: Small-caliber vascular grafts; biomechanical features; cell infiltration; decellularization matrices.