Injectable, High Modulus, And Fatigue Resistant Composite Scaffold for Load-Bearing Soft Tissue Regeneration

High modulus, two-phase, bicontinuous scaffolds were prepared by photocross-linking an aqueous suspension of chondrocytes and N-methacrylate glycol chitosan with a hydrolyzable, hydrophobic, acrylated star-copolymer. Two acrylated star-copolymers were examined: poly(epsilon-caprolactone-co-D,L-lactide) (5446DLLACL) and poly(epsilon-caprolactone-co-trimethylene carbonate) (7030TMCCL). The scaffolds were assessed for injectability, two-phase interconnectivity, fatigue resistance, and long-term static culture behavior. The 7030TMCCL scaffolds demonstrated decreased moduli of 17% after 1 X 10(6) cycles at 30% strain and 5% after 56 days in culture, compared to the 5446DLLACL scaffolds, which exhibited decreases of 58 and 68%, respectively. The 7030TMCCL scaffolds accumulated more extracellular matrix after 56 days of culture (GAG: 20.1 +/- 1, collagen: 35.5 +/- 1.8 mu g) compared to 5446DLLACL scaffolds (GAG: 13.2 +/- 0.6, collagen: 6.2 +/- 3.4 mu g). Overall, the 7030TMCCL-based scaffolds were shown to be better suited for use as a load bearing soft tissue scaffold.