Regeneration of the Intervertebral Disc with Nucleus Pulposus Cell-Seeded Collagen II/Hyaluronan/Chondroitin-6-Sulfate Tri-Copolymer Constructs in a Rabbit Disc Degeneration Model

Abstract

Introduction Advancement in tissue engineering provides a promising approach to recover the functionality of the degenerated intervertebral disc. In our study, a nucleus pulposus (NP) cell-seeded collagen II/hyaluronan/chondroitin-6-sulfate (CII/HyA/CS) tri-copolymer construct was implanted into the disc space directly after nucleotomy in a rabbit model. The aim of this study was to investigate whether the NP cell-seeded CII/HyA/CS tri-copolymer constructs could regenerate the degenerated disc in vivo after implantation into the rabbit nucleotomy model. Materials and Methods NP cells isolated from thoracic and lumbar spines of New Zealand white rabbits of about 3 weeks of age and 1 kg in weight were labeled with a 5- (and-6)-carboxyflurescein diacetate succinimidyl ester (CFDA-SE) fluorescent dye and seeded within the CII/HyA/CS scaffold by a centrifugation method. After in vitro culture for 1 week, NP cell-seeded CII/HyA/CS tri-copolymer constructs were allografted into the disc defects of recipient rabbit immediately after nucleotomy of the lumbar spine. The Bradner disc index and the T2-weighted signal intensity index were determined using lateral plane radiographs and magnetic resonance imaging at 4, 12, and 24 weeks after the operation. Finally, the operated discs were explanted for gross morphological observation, histological evaluation, and cell viability assessment. Animals with only nucleotomy and cell-free CII/HyA/CS scaffold implantation served as controls. Results In our study, we could demonstrate that the T2-weighted signal intensity index of the operated discs decreased in all three groups 1 month after surgery and the index of the cell-containing scaffold insertion group was significantly higher than that of the other two groups. After 24 weeks, the index of the cell-containing scaffold insertion group increased significantly. However, further decline was observed in both the noninsertion group and the scaffold insertion group. In radiographic analysis, the narrowing of the intervertebral disc space was significantly retarded by the cell-scaffold hybrids implantation up to 24 postoperative weeks. Moreover, the gross morphology and histological evaluation indicated that the allografted NP cells were viable and showed extracellular matrix production. Conclusion In our study, we had constructed rabbit NP cell-seeded CII/HyA/CS tri-copolymer implants in vitro. Immediately after nucleotomy of the recipient rabbit, we allografted the precultured cell-scaffold hybrids into the lacuna of the disc. Results documented survival of the allografted NP cells and extracellular matrix deposition, which finally resulted in maintenance of disc height and restoration of T2-weighted signal intensity on magnetic resonance imaging. Disclosure of Interest None declared

Mesenchymal progenitor cells combined with pentosan polysulfate mediating disc regeneration at the time of microdiscectomy: a preliminary study in an ovine model

“…1,2,10,16,20,22,25,[30][31][32][34][35][36][37][38]46,48,49,53,54,56,57,60,62,[64][65][66][67]69,73,83,90 The EuroDISC study, by Meisel and colleagues, 49 investigated the percutaneous transplantation of autologous disc chondrocytes. Following microdiscectomy, disc chondrocytes were harvested and expanded in vitro and were subsequently injected into the NP 3 months postoperatively.…”

Establishment of a Promising Human Nucleus Pulposus Cell Line for Intervertebral Disc Tissue Engineering

“…Originally, for disc regeneration, primary chondrocytes such as NP cells were used in the model for regeneration. 14,17 However, primary chondrocytes isolated from cartilaginous tissue lost its phenotype, including the decreased cell proliferation and matrix synthesis during expanded culture. The process of primary culture is also inconvenient to gain sufficient cell materials for model insight into regenerative medicine.…”

Reconstitution of degenerated ovine lumbar discs by STRO-3–positive allogeneic mesenchymal precursor cells combined with pentosan polysulfate

“…Preclinical and clinical studies have used mesenchymal stem cells (MSCs) and the chondrocyte-like cells derived from the nucleus pulposus (NP) of the disc or juvenile articular cartilage to repair the intervertebral disc. 1,2,7,[13][14][15][22][23][24][25][26][27][28][29][30]38,39,57,59,74,75 Unlike disc chondrocytes, MSCs can be readily isolated from a variety of tissues including bone marrow, adipose tissue, and synovium. 9,76 Moreover, MSCs possess the capacity for self-renewal and thus maintain their undifferentiated phenotype in multiple subcultures, but when they are exposed to the appropriate stimuli, they can undergo differentiation into cells of the mesenchymal lineage, such as chondrocytes, osteocytes, and adipose cells.…”