Cell sheet engineering in the periodontal regeneration

Objective: Stem cell-based therapy represents a novel and advantageous modality of treatment for periodontitis. However, this strategy is puzzled by central issues such as the predictable amount and the approaches of stem cell needed for the periodontal transplantation. In order to ensure the function of transplanted PDLSC, a novel cell sheet strategy was chosen as the alternative modality of the stem cell transplantation . On the basis of our above research, in order to raise the mechanical properties, strata and manipulation convenience of the cell sheet, we hypothesized that the fabrication of the PDLSc cell sheet combined with CBB and Bio-ss particles.

Methods: PDLSC cell sheet was fabricated using the SD rat PDLSC . In order to observe the different time of the combination of the CBB and Bio-ss particles on the PDLSC cell sheet cultivation and properties, we designed six time spots for the observation: sham, 1d, 2d, 3d, 6d, 10d after the cell seeding. Then we observed the changes of the formation of extracellular matrix , the time of harvest, the thickness of the cell sheet using hitological evaluation and SEM. We further constructed the periodontitis model in SD rats, and transplanted the cell sheet .

Results:The combined cell sheet retained the ultrastructure of conventional cell sheet, had better biocompatibility and mechanical properties. The in vivo differentiation assay of PDLSC cell sheet alone produced periodontal tissue healing with bone, periodontal ligament and cementum formation; PDLSCs cell sheet combined with CBB/dentin particles showed more prominent periodontal regeneration in the defect height ,new bone formation ,new cementum ,connective tissue attachment(P<0.05).

Conclusion:The PDLSC cell sheet combined with the CBB or Bio-ss particles may serve as a promising stem cell delivery vehicle .