Chronic kidney disease and stromal cell-derived factor 1α peptide-functionalization impact on polycarbonate-bisurea based in situ tissue-engineered vascular graft dynamics

This study evaluated how chronic kidney disease and SDF-1α peptide functionalization influence the remodeling dynamics of rapidly degrading polycarbonate-bisurea in situ tissue-engineered vascular grafts. Electrospun PC-BU and PC-BU + SDF-1α small-diameter vascular grafts were implanted as rat abdominal aortic interposition grafts in sham and 5/6th-nephrectomy CKD rats. At two weeks, patency was 100% in both sham and CKD groups, with explants showing endothelial lining formation, smooth muscle cell markers, macrophage infiltration, collagen deposition, and early graft degradation. CKD did not measurably alter early patency, neo-tissue formation, inflammation, graft degradation, or mechanical stability, and SDF-1α functionalization similarly did not improve early vascular tissue formation or mechanical outcomes. Three-month sham explants remained patent but showed major lumen dilation, aneurysm-like remodeling, calcification trends, and reduced inflammation, while additional sham animals experienced graft rupture and fatal abdominal bleeding from three weeks onward. SEM showed progressive fiber erosion and breakage, indicating that scaffold degradation outpaced the load-bearing maturation of the developing neo-tissue in some cases. Overall, the study shows that rapidly degrading PC-BU grafts can accelerate vascular neo-tissue formation, but that long-term mechanical stability remains a key design challenge for in situ tissue-engineered blood vessels.