A fibrochondrogenic polymer fibre-reinforced collagen-based scaffold with graded architecture, mechanics and composition for meniscus repair

Developing biomaterials for meniscal repair that reproduce native tissue biomechanics while providing pro-regenerative bioinstructive cues remains challenging. To address this need, we developed a zonal biomimetic fibre-reinforced collagen-based scaffold designed to recreate key microstructural and mechanical features of the meniscus and support fibrochondrogenesis in vitro. A multilayer scaffold was fabricated with a circumferential electrospun (ES) fibre core composed of polycaprolactone (PCL), polylactic acid (PLA), or a hybrid PCL/polyvinyl alcohol (PVA)/PLA reinforcement, together with radially oriented melt-electrowritten (MEW) PCL intermediate zones and multidirectional MEW PCL superficial zones, followed by integration with a collagen I-chondroitin-6-sulfate matrix. Fibre-reinforced scaffolds combining MEW PCL with the hybrid ES PCL-PVA-PLA reinforcement framework demonstrated the best-balanced biomechanical performance, achieving mechanical properties within the range reported for native meniscus under comparable test conditions, including tensile, compressive and complex moduli of 140.62 ± 26.31 MPa, 723.21 ± 147.09 kPa and 25.91 ± 1.21 kPa, respectively. Moreover, human bone marrow-derived mesenchymal stem cells cultured on this scaffold exhibited enhanced sulfated glycosaminoglycan production, balanced type I and type II collagen expression, and fibrocartilage-like extracellular matrix deposition with the reinforced architecture supporting deeper and more uniform matrix formation. Together, these findings support zonal fibre reinforcement as a design strategy to integrate mechanical fidelity with scaffold-dependent modulation of hMSC fibrochondrogenesis in vitro, identifying the hybrid PCL-PVA-PLA-reinforced scaffold as a best-balanced configuration for meniscal repair.