Electrospun polyurethane-based vascular grafts: physicochemical properties and functioning in vivo

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Vascular Surgery

Background:

• Vascular grafts are crucial for replacing damaged or diseased blood vessels.
• Expanded polytetrafluoroethylene (e-PTFE) is a common synthetic vascular graft material.
• Challenges with current grafts include thrombosis, intimal hyperplasia, and limited integration with host tissue.

Purpose of the Study:

• To investigate the physicochemical properties and in vivo performance of electrospun vascular grafts (VGs) composed of Tecoflex (Tec), gelatin (GL), and bivalirudin (BV).
• To compare the efficacy of these novel Tec-GL-BV VGs against expanded polytetrafluoroethylene (e-PTFE) grafts in a rat abdominal aorta model.

Main Methods:

• Electrospinning was used to fabricate Tec-GL-BV vascular grafts.
• Vascular grafts were implanted into the abdominal aortas of 36 Wistar rats.
• Graft performance was evaluated over 24 weeks, including assessments of patency, neovascularization, neointima thickness, and calcification.

Main Results:

• Tec-GL-BV grafts exhibited significantly higher patency rates (94.5%) compared to e-PTFE grafts (66.6%) after 6 months (p=0.0438).
• Severe neovascularization was observed in the neoadventitial layer of Tec-GL-BV grafts, surpassing that of e-PTFE grafts.
• Histological analysis revealed reduced neointima thickness and lower calcification levels in Tec-GL-BV grafts compared to controls.

Conclusions:

• Polyurethane-based, protein-enriched vascular grafts demonstrate superior performance over e-PTFE grafts in a preclinical setting.
• The enhanced neovascularization and reduced intimal hyperplasia suggest improved biocompatibility and integration.
• These findings support the potential clinical utility of Tec-GL-BV vascular grafts.