Intervertebral disc tissue engineering using a novel hyaluronic acid-nanofibrous scaffold (HANFS) amalgam

Degeneration of the intervertebral disc (IVD) represents a significant musculoskeletal disease burden. Although spinal fusion has some efficacy in pain management, spine biomechanics is ultimately compromised. In addition, there is inherent limitation of hardware-based IVD replacement prostheses, which underscores the importance of biological approaches to disc repair. In this study, we have seeded multipotent, adult human mesenchymal stem cells (MSCs) into a novel biomaterial amalgam to develop a biphasic construct that consisted of electrospun, biodegradable nanofibrous scaffold (NFS) enveloping a hyaluronic acid (HA) hydrogel center. The seeded MSCs were induced to undergo chondrogenesis in vitro in the presence of transforming growth factor-beta for up to 28 days. The cartilaginous hyaluronic acid-nanofibrous scaffold (HANFS) construct architecturally resembled a native IVD, with an outer annulus fibrosus-like region and inner nucleus pulposus-like region. Histological and biochemical analyses, immunohistochemistry, and gene expression profiling revealed the time-dependent development of chondrocytic phenotype of the seeded cells. The cells also maintain the microarchitecture of a native IVD. Taken together, these findings suggest the prototypic potential of MSC-seeded HANFS constructs for the tissue engineering of biological replacements of degenerated IVD.