No abstract

Degeneration of the intevertebral disc 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 nanofiber 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-β for up to 28 days. The cartilaginous HANFS construct architecturally resembled a native intervertebral disc, with an outer annulus fibrosus (AF)-like region and inner nucleus pulposus (NP)-like region. Histological and biochemical analyses, immunohistochemistry, and gene expression profiling revealed the time-dependent development of chondrocytic phenotype of the seeded cells. Taken together, these findings suggest the prototypic potential of MSC-seeded HANFS constructs for the tissue engineering of biological replacements of degenerated IVD.

Defining injuries as acute or chronic is clinically relevant in many cases, particularly concerning tendon injuries, where these terms have implications regarding the anatomic pathologic changes and tissue quality, which may necessitate augmentation and alter the initial surgical plan. In cases where these terms are less pertinent to operative treatment considerations, they bring clarity to the discussion of the acuity of the injury (as it pertains to time from insult).