Engineering biodegradable polyester elastomers with antioxidant properties to attenuate oxidative stress in tissues

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Oxidative stress contributes to poor biomaterial biocompatibility and vascular pathologies like atherosclerosis.
• Developing materials with inherent antioxidant capabilities can mitigate these issues.
• Biodegradable polymers with built-in antioxidants offer sustained local attenuation of oxidative stress.

Purpose of the Study:

• To synthesize and characterize a novel biodegradable elastomer, poly(1,8-octanediol-co-citrate-co-ascorbate) (POCA), with intrinsic antioxidant properties.
• To evaluate the in vitro and in vivo antioxidant activity and cellular effects of POCA.
• To assess the potential of POCA in tissue engineering applications, particularly concerning oxidative stress.

Main Methods:

• Synthesis of POCA, a citric-acid based biodegradable elastomer.
• In vitro assessment of antioxidant properties: free radical scavenging, iron chelation, lipid peroxidation inhibition.
• In vitro studies on vascular cells (viability, proliferation) and in vivo evaluation using POCA-coated ePTFE grafts.

Main Results:

• POCA exhibited significant antioxidant activity, including reactive oxygen species scavenging and protection against oxidative stress-induced cell death.
• Antioxidant properties of POCA were maintained even after polymer degradation.
• POCA supported endothelial cell proliferation while inhibiting smooth muscle cell proliferation, and POCA-coated grafts showed reduced intimal hyperplasia.

Conclusions:

• POCA is a biodegradable elastomer with intrinsic antioxidant properties, effective in scavenging free radicals and inhibiting lipid peroxidation.
• The material demonstrates cytocompatibility and modulates vascular cell proliferation, showing promise for tissue engineering.
• POCA's sustained antioxidant activity and beneficial effects on vascular cells suggest its utility in applications where oxidative stress is a concern, such as vascular graft coatings.