Biodegradable and elastomeric vascular grafts enable vascular remodeling

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Vascular Surgery

Background:

• Implanted vascular grafts undergo host cell remodeling, posing challenges for regenerative medicine.
• Designing grafts that promote constructive remodeling is crucial for successful tissue regeneration.

Purpose of the Study:

• To develop a biodegradable elastic polymer graft with aligned microfibers to guide vascular regeneration.
• To evaluate the in vivo performance of the poly (l-lactide-co-ε-caprolactone) (PLCL) graft in promoting neoartery formation.

Main Methods:

• Fabrication of circumferentially aligned microfiber grafts using poly (l-lactide-co-ε-caprolactone) (PLCL).
• Implantation of PLCL grafts into rat abdominal aortas.
• Assessment of graft remodeling, cell infiltration, endothelialization, macrophage response, cytokine expression, and degradation over 12 months.
• Characterization of the regenerated neoartery's structure, mechanical properties, and vasomotor function.

Main Results:

• PLCL grafts demonstrated excellent handling and resistance to deformation.
• Rapid cell infiltration, alignment, and complete endothelialization were observed within 4 weeks.
• A high M2/M1 macrophage ratio and transient cytokine expression indicated controlled inflammation.
• By 12 months, PLCL grafts were nearly degraded, replaced by a neoartery with native-like characteristics, including mechanical properties and vasomotor response.

Conclusions:

• The designed PLCL vascular graft effectively guides constructive tissue remodeling and regeneration.
• This strategy offers a new approach for guided tissue regeneration by controlling scaffold properties.
• The developed graft successfully regenerated a functional neoartery, comparable to native vessels.