Biological and Mechanical Factors Promote the Osteogenesis of Rabbit Artificial Vertebral Laminae: A Comparison Study.

Reconstruction of vertebral laminae without epidural scar formation has been challenging. The success of bone formation depends on the biological and mechanical conditions of the surrounding tissues. In this study, we aimed to investigate the roles of biological and mechanical factors in the osteogenesis of artificial laminae. Mesenchymal stem cells derived from rabbit umbilical cord Wharton's jelly were induced for osteogenic differentiation for 3 weeks before seeding on the hydroxyapatite-collagen I scaffolds to construct the tissue-engineered laminae (TEL). TEL were then implanted into the fifth rabbit lumbar vertebrae in both orthotopic lamina (n = 30) and ectopic lamina (n = 30) groups. De novo laminae were examined through histological and radiographic analysis in the 2nd, 4th, 8th, 12th, and 16th weeks postimplantation. Our results showed that de novo laminae formed effectively in both groups, and the osteogenic gene expression levels and cancellous microstructure parameters of de novo laminae in the orthotopic lamina group were significantly higher than those in the ectopic lamina group. In conclusion, the biological stimulation of bone defect initiated the early onset osteogenesis, and the mechanical stimulation of cerebrospinal fluid pulsation stress promoted the osteogenesis of de novo laminae.