Self-healing and cell-free vascular grafts

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Vascular Grafts

Background:

• Vascular access conduits are crucial for hemodialysis.
• Current grafts face challenges like thrombosis and mechanical failure.
• Need for improved biomaterials with self-healing properties.

Purpose of the Study:

• To develop and evaluate a novel self-healing tissue engineering vessel (SH-TEV).
• To assess the mechanical properties, self-healing capacity, and in vivo performance of the SH-TEV.
• To determine the potential of SH-TEVs as vascular access conduits.

Main Methods:

• Fabrication of a bilayer SH-TEV using electrospun polyurethane (PU-DAA) and small intestinal submucosa (SIS).
• Characterization of mechanical strength, toughness, and autonomous self-healing of PU-DAA.
• In vivo implantation of SH-TEVs as interpositional grafts in rat aortas for 4 weeks.
• Assessment of graft patency, endothelialization, vascular wall development, and self-healing post-puncture.

Main Results:

• The self-healing PU-DAA layer demonstrated high strength (3.95 MPa) and toughness (23.01 MJ/m³).
• SH-TEVs exhibited rapid autonomous self-healing (86.44% after 12h) and biocompatibility with fibroblasts.
• In vivo studies showed 100% graft patency and survival, with successful endothelialization and vascular wall formation.
• SH-TEVs demonstrated excellent hemostasis (<40s) after needle puncture, both immediately and post-implantation.

Conclusions:

• The developed SH-TEV possesses excellent mechanical properties and rapid self-healing capabilities.
• SH-TEVs are biocompatible and promote host cell integration, forming a functional vascular wall in vivo.
• These findings highlight the significant potential of SH-TEVs as advanced vascular access conduits for hemodialysis.