Odontogenic Potential of Dental Pulp Cells Mediated by Calcium-Aluminate-Enriched Scaffold

Objectives: The objective of this study was to evaluate the odontogenic potential of human dental pulp cells (HDPCs) in contact with an experimental porous chitosan-collagen scaffold (CHC) enriched or not with a mineral phase of calcium-aluminate (CHC-CA).
Methods: To assess the chemotactic effect of the materials, the HDPCs were seeded on transwell membranes (8 um pore) in intimate contact with the CHC or CHC-CA surface, and the cell migration was monitored at 24 and 48 hours. Additionally, cells were seeded onto the materials surface, and the viability (live/dead assay) and proliferation (alamar blue) were evaluated at 1, 7, 14, 21 and 28 days. To assess the odontoblastic differentiation, ALP activity (thymolphthalein/14 days), DSPP/DMP-1 gene expression (real-time PCR/28 days) and mineralized matrix deposition (micro-CT/28 days) were evaluated. HDPCs cultured onto a polystyrene surface (PS) were used as negative control group (ANOVA/Tukey’s test a=5%).
Results: Significantly lower number of cells was observed on the up-side of the transwell membrane for the CHC and CHC-CA groups in comparison with that on the PS group at both time-points, with CHC-CA featuring significantly lower cells than CHC group. The HDPCs seeded onto both CHC and CHC-CA scaffold were capable of migrating inside it and remaining viable at all time-points. For the CHC-CA group, significantly increased cell metabolism was observed at the 7- and 14-day time-points relative to CHC and PS groups, whereas the CHC group featured significantly higher cell metabolism compared with PS group only at 7 days of cell culture. At long-term culture, cells in the CHC-CA scaffold featured the highest deposition of mineralized matrix and expression of odontoblastic markers (ALP activity and DSPP/DMP-1 gene expression) relative to PS and CHC groups (p<0.05).
Conclusions: Therefore, the CHC-CA scaffold acted as a chemotactic, cytocompatible and bioactive substrate, capable of increasing the odontogenic potential of human pulp cells.