In Vitro Repair of Meniscal Radial Tear Using Aligned Electrospun Nanofibrous Scaffold

Radial tears of the meniscus represent one of the most common injuries of the knee, and result in loss of biomechanical meniscal function. However, there have been no established, effective treatments for radial meniscal tears. Nanofibrous materials produced by electrospinning have shown high promise in the engineering of soft musculoskeletal tissues. The goal of our study is to apply these technologies to develop a functional cell-seeded scaffold as a potential, new surgical method to enhance meniscal radial repair. Cylinder-shaped explants were excised from the inner avascular region of bovine meniscus and a radial tear was created in the center of the explant. The torn site was wrapped with either nanofibrous scaffold alone or scaffold seeded with meniscal fibrochondrocytes (MFC). A control group was prepared as explants without scaffolds or cells. The composite constructs in each group were cultured in vitro for 4 and 8 weeks, and these were then assessed histologically and mechanically. Histological analysis showed partial repair of the radial tear was observed with adherence between scaffold and native meniscal tissue in either the scaffold alone or cell-seeded scaffold group. Only the cell-seeded scaffold exhibited significant positive Picrosirius red staining and Safranin O staining. Mechanical testing of the repaired meniscus showed that the load-to-failure and stiffness values were significantly improved in the cell-seeded group. These results demonstrated the applicability of the MFC-seeded nanofibrous scaffold for meniscal radial tear repair based on both histological and mechanical analyses. In particular, the highly adhesive property of the cell-seeded scaffold to the meniscal tissue should be beneficial in helping to preserve the meniscal function by stabilizing meniscal fibers.