Biodegradable Polyurethanes for Tissue Engineering: Influence of L-Lactide Content on Degradation and Mechanical...

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Tissue Engineering

Background:

• Tissue scaffolds require tailored mechanical properties and degradation rates matching host tissues.
• Biodegradable polyurethanes (PUs) are candidates for tissue engineering, but their properties need optimization.
• Incorporating L-lactide into poly(caprolactone) segments can disrupt crystallinity and enhance degradation.

Purpose of the Study:

• To investigate the impact of L-lactide content on the degradation and properties of biodegradable polyurethanes (PUs).
• To evaluate the influence of molecular weight, L-lactide content, and hard segment crystallinity on PU mechanical behavior and water absorption.
• To assess the cytocompatibility of developed PUs using an endothelial cell model.

Main Methods:

• Synthesis of biodegradable PUs using copolymers with varying L-lactide content (15-43%) as soft segments.
• Characterization via physicochemical techniques, including molecular weight determination, water absorption, and mechanical testing.
• Cytocompatibility assessment using endothelial cell metabolic activity and DNA content analysis.

Main Results:

• Mechanical properties and water absorption were significantly influenced by molecular weight, L-lactide content, and hard segment crystallinity.
• Polyurethanes (PUs) utilizing hydrolysable chain extenders exhibited higher molecular weights and superior mechanical performance compared to those with non-hydrolysable extenders.
• In vitro assays confirmed good cell adhesion and no toxicity, indicating the viability of cell growth on the PU surfaces.

Conclusions:

• Biodegradable polyurethanes with tunable mechanical properties and adjustable degradation profiles were successfully synthesized.
• The L-lactide content in the soft segments critically affects PU characteristics, enabling property modulation for specific tissue engineering applications.
• Developed PUs demonstrate excellent biocompatibility and mechanical suitability, positioning them as promising materials for biodegradable biomedical applications in tissue engineering.