Ex vivo endothelialized cECM-enriched core-shell fibrous vascular graft promotes rapid regenerative remodeling in vivo.

Abstract

Occlusive arterial disease continues to be a leading contributor to morbidity and mortality, and the ongoing lack of small-diameter vascular grafts (<6 mm) significantly restricts surgical interventions. In this work, we present a new core/shell fibrous vascular graft (C/S PE) created through coaxial electrospinning, consisting of a polycaprolactone (PCL) core and a cardiac extracellular matrix (cECM)-enriched shell designed for ex vivo endothelialization. Proteomic profiling confirmed that the cECM preserved angiogenic and cell-adhesive components capable of guiding vascular lineage commitment. To enhance luminal cellular organization prior to implantation, a dynamic ex vivo perfusion strategy was applied to induce mesenchymal stem cell differentiation under gradually increasing shear conditions designed to emulate early physiological adaptation. This approach enabled the formation of a confluent endothelial-like layer after two weeks. RNA-seq analysis revealed activation of pathways associated with endothelial proliferation, angiogenesis, extracellular matrix remodeling, etc. Following implantation in the rat abdominal aorta model, the ex vivo endothelialized (C/S PE-EC) grafts maintained 100% patency and progressive host-driven remodeling characterized by endothelial regeneration, smooth muscle layer formation, and a shift toward a pro-healing macrophage phenotype. Importantly, the C/S PE (EC) grafts reached nearly complete endothelial coverage and functional eNOS expression within one month, suggesting the synergistic role of biomimetic matrix composition and biomechanical conditioning in accelerating vascular integration. By integrating synthetic strength, ECM bioactivity, and stem cell-derived endothelialization, this approach offers a promising pathway toward clinically translatable small-diameter vascular grafts, particularly appropriate for scheduled procedures such as Fontan surgery and hemodialysis access.