Effects of Co-Culture of Dental Pulp Stem Cells and Periodontal Ligament Stem Cells on Assembled Dual Disc Scaffolds

The study of cell-to-cell interaction in experimental co-culture systems is very important and relevant to the context of biomaterial scaffolds used for tissue regeneration. In this study, scaffolds, which allow direct and indirect cell-to-cell contact and separation of each cell type, were developed using one of the most utilized biopolymer, poly-D, L-lactide (PDLLA). The assembled scaffold had enough mechanical strength to withstand experiments and maintain its shape. It is separated easily into core and outer portion for further experiments, which could be conducted to examine the effects of co-culture. Co-culture with dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs) increased proliferation of both cell types and dentin sialophosphoprotein (DSPP) mRNA expression in co-cultured PDLSCs. In immunohistochemical examination, dentin sialoprotein (DSP) expression in both cell types was up-regulated in co-culture compared to that of mono-culture. The longer the culture period, the more DSP expressions were up-regulated. Osteopontin (OPN) expression in both cell types was also up-regulated in co-culture. Co-culture of dental stem cells improved cell proliferation and osteogenic differentiation. This study demonstrates that biomimetic co-culture method for tooth tissue engineering may be potentially applied to study dental stem cell behavior in tooth regenerative medicine.