Odontogenic induction of human amniotic membrane scaffold for dental pulp regeneration

This study aimed to investigate the ability of glycerol or cryopreserved de-epithelialized human amniotic membrane, coded as GAM or CAM respectively, to induce odontogenic differentiation of deciduous teeth stem cells (DTSCs) cultured on their stromal (coded as GAMS or CAMS) or basal sides (coded as GAMB or CAMB). The DTSCs attachment, proliferation, dentinogenic differentiation (COL-1, DMP1, ALP, and Nestin) and inflammatory cytokines (TGF-β, IL-β, IL-6, IL-8, GM-CSF and TNF-α) expression were evaluated. Furthermore, dental pulp stem cells (DPSCs)-seeded on GAM was transplanted into a prepared root canal for 3-day, and cells attachment to dentine was investigated. Both GAM and CAM supported DTSCs attachment. DTSCs showed significantly higher proliferation after 7 days when seeded on both sides of CAM than on GAM, but both were still significantly lower than the control. There was no significant difference in cell proliferation between the stromal and basal sides of the same membrane. The expression of odontogenic markers of cells seeded on the membranes was comparable to the control cells, except for ALP. The expression of ALP on both sides of GAM was significantly higher than those on CAM, indicating the possible odontogenic differentiation potential of GAM. The differentiation could also explain the higher proliferation of cells grown on CAM compared to GAM. This finding was also consistent with the higher expression of IL-8 on CAM than GAM. When GAM was used to deliver DPSCs to the dentin of the root canal, no cells were observed on the dentin surface, indicating the strong attachment of cells to GAM. The findings warrant further investigation. GAM could be used as a scaffold for pulp regeneration while vascularization and toning the degradation of GAM to be consistent with the new tissue formation will be considered for future work.