Rapid Cartilage Regeneration of Spheroids Composed of Human Nasal Septum-Derived Chondrocyte in Rat Osteochondral Defect Model

Background: Cell-based therapies have been studied for articular cartilage regeneration. Articular cartilage defects have little treatments because articular cartilage was limited regenerative capacity. Damaged articular cartilage is difficult to obtain a successful therapeutic effect. In additionally these articular cartilage defects often cause osteoarthritis. Chondrocyte implantation is a widely available therapy used for regeneration of articular cartilage because this tissue has poor repair capacity after injury. Human nasal septum-drived chondrocytes (hNCs) from the septum show greater proliferation ability and chondrogenic capacity than human articular chondrocytes (hACs), even across different donors with different ages. Moreover, the chondrogenic properties of hNCs can be maintained after extensive culture expansion. Methods: In this study, 2 dimensional (2D) monolayer cultured hNCs (hNCs-2D) and 3 dimensional (3D) spheroids cultured hNCs (hNCs-3D) were examined for chondrogenic capacity in vitro by PCR and immunofluorescence staining for chondrogenic marker, cell survival during cultured and for cartilage regeneration ability in vivo in a rat osteochondral defect model. Results: hNCs-3D showed higher viability and more uniform morphology than 3D spheroids cultured hACs (hACs-3D) in culture. hNCs-3D also showed greater expression levels of the chondrocyte-specific marker Type II collagen (COL2A1) and sex-determining region Y (SRY)-box 9 (SOX9) than hNCs-2D. hNCs-3D also expressed chondrogenic markers in collagen. Specially, in the osteochondral defect model, implantation of hNCs-3D led to greater chondrogenic repair of focal cartilage defects in rats than implantation of hNCs-2D. Conclusion: These data suggest that hNCs-3D are valuable therapeutic agents for repair and regeneration of cartilage defects.