Novel biphasic elastomeric scaffold for small-diameter blood vessel tissue engineering.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Clinical implementation of tissue-engineered small-diameter blood vessels (SDBVs) faces challenges like compliance mismatch and thrombosis.
• Existing SDBV approaches require long in vitro culture times.

Purpose of the Study:

• To develop an implantable, elastomeric, and biodegradable biphasic tubular scaffold for SDBVs.
• To mimic the intimal and medial layers of a native blood vessel using distinct scaffold phases.

Main Methods:

• Fabrication of biphasic scaffolds from poly(diol citrate), a novel biodegradable polyester elastomer.
• Characterization of scaffold properties: mechanical (tensile, compressive, burst pressure, compliance), foreign body reaction (subcutaneous implantation in rats), and cellular behavior (histology, SEM, immunohistochemistry).
• In vitro coculture of human aortic smooth muscle cells (HASMCs) and human aortic endothelial cells (HAECs) on the scaffolds.

Main Results:

• Biphasic scaffolds exhibited mechanical properties similar to native vessels, with appropriate compliance and burst pressure.
• Scaffolds demonstrated good biocompatibility, forming a thin fibrous capsule and allowing tissue ingrowth after implantation.
• In vitro studies confirmed scaffold ability to support cell compartmentalization, coculture, and differentiation, with HAECs forming a von Willebrand factor-positive monolayer and HASMCs expressing collagen and calponin.

Conclusions:

• The developed biphasic scaffold shows promise for SDBV applications by addressing key challenges in tissue engineering.
• The scaffold design effectively supports cellular organization and differentiation, mimicking native vessel structure and function.
• Poly(diol citrate) elastomers offer a viable material for creating functional, tissue-engineered vascular grafts.