Detalhes do Documento

Meniscus injuries are among the most prevalent musculoskeletal disorders and a major risk factor for the development and progression of knee osteoarthritis. The intrinsic healing capacity of the meniscus is severely limited, particularly in the inner avascular region, where approximately 70% of lesions occur, restricting the effectiveness of current surgical repair strategies. Although regenerative approaches have shown promising results supporting the mechanical support needed, they often lack biological cues required for cell attachment and matrix formation. To address the inherent trade-off between strength and bioactivity, this study develops a coaxial printing strategy to engineer core–shell constructs, for meniscus tissue engineering. The coaxial extrusion technique enabled the simultaneous extrusion of two distinct inks through a single nozzle, creating a 3D strand composed by a core and a shell. A polycaprolactone (PCL) core provides mechanical reinforcement, while a silk fibroin (SF) shell promotes cell adhesion ensuring the integrity of the 3D constructs. Rheological characterization was performed to optimize printability. 3D constructs were printed and analyzed in terms of morphology and mechanical performance. Finally, human primary fibrochondrocytes (HFC) were seeded onto the scaffolds to access cell adhesion, metabolic activity, proliferation, and extracellular matrix production. The developed coaxial inks showed adequate rheological properties for printability and structural fidelity. Scanning electron microscopy (SEM) analysis confirmed the distinct core–shell architecture of the printed constructs. Mechanical testing revealed that the 3D constructs achieved compressive and radial tensile moduli of 2.25 ± 0.25 MPa and 13.61 ± 2.91 MPa, respectively, closely mimicking the mechanical performance of the native meniscus.[1]Biologically, the SF shell improved early cell-scaffold interactions, increasing the metabolic activity (Alamar Blue assays) and proliferation versus PCL controls. Furthermore, higher glycosaminoglycan and collagen contents in PCL-SF scaffolds indicated enhanced extracellular matrix deposition. Confocal imaging further confirmed that HFC maintained a healthy morphology and successfully attached to the SF shell. Overall, this coaxial PCL/SF approach generated scaffolds with improved mechanical and biological performance over PCL controls, supporting its potential as a bioactive platform for meniscus repair and regeneration. This work represents a significant step toward overcoming the limitations of current non-regenerative orthopedic treatments.