Fast-degrading bioresorbable arterial vascular graft with high cellular infiltration inhibits calcification of the graft

Objective Bioresorbable vascular grafts are biologically active grafts that are entirely reconstituted by host-derived cells through an inflammation-mediated degradation process. Calcification is a detrimental condition that can severely affect graft performance. Therefore, prevention of calcification is of great importance to the success of bioresorbable arterial vascular grafts. The objective of this study was to test whether fast-degrading (FD) bioresorbable arterial grafts with high cellular infiltration will inhibit calcification of grafts. Methods We created two versions of bioresorbable arterial vascular grafts, slow-degrading (SD) grafts and FD grafts. Both grafts had the same inner layer composed of a 50:50 poly(L-lactic-co-ε-caprolactone) copolymer scaffold. However, the outer layer of SD grafts was composed of poly(L-lactic acid) nanofiber, whereas the outer layer of FD grafts was composed of a combination of poly(L-lactic acid) and polyglycolic acid nanofiber. Both grafts were implanted in 8- to 10-week-old female mice (n = 15 in the SD group, n = 10 in the FD group) as infrarenal aortic interposition conduits. Animals were observed for 8 weeks. Results von Kossa staining showed calcification in 7 of 12 grafts in the SD group but zero in the FD group (P <.01, χ² test). The cell number in the outer layer of FD grafts was significantly higher than in the SD grafts (SD, 0.87 ± 0.65 × 10³/mm²; FD, 2.65 ± 1.91 × 10³/mm²; P =.02). Conclusions The FD bioresorbable arterial vascular graft with high cellular infiltration into the scaffold inhibited calcification of grafts.