Fabrication and characterization of electrospun nanofibers composed of decellularized meniscus extracellular matrix and polycaprolactone for meniscus tissue engineering

Many kinds of scaffolds have been produced in meniscus tissue engineering, but few have matched the mechanical properties of native meniscus, making it impossible for them to sustain large stress at initial implantation. In this study, we used a differential centrifugation method to obtain decellularized meniscus extracellular matrix (DMECM) and combined the DMECM with polycaprolactone (PCL) via electrospinning to fabricate random and aligned microfibers. The FTIR results and biochemical assays demonstrated the successful mixing of these two elements, and the addition of DMECM improved the hydrophilicity of the microfibers. The blending of DMECM also enhanced the tensile modulus of the microfibers, and aligned fibers had tensile moduli ranging from 132.27 to 331.40 MPa, which match that of human meniscus. In addition, we defined yield stress as the lose-efficacy point. The results showed that DMECM/PCL fibers had higher yield stresses than the pure PCL fibers, and the aligned fibers had higher yield stress values than the randomly oriented fibers. Nanoindentation results showed that adding DMECM had no significant impact on modulus and hardness with the exception of fibers containing 80% DMECM, which exhibited an obvious increase in modulus. In vitro assay demonstrated that the DMECM/PCL fibers had no hemolysis or cytotoxicity. Meniscus cells could attach and proliferate on the fibers, and the fiber orientation had a direct influence on cell arrangement. RT-PCR results showed that meniscus cells had higher gene expressions of aggrecan, collagen I, collagen II and Sox 9 when seeded on fibers with higher DMECM contents.