Graphene oxide quantum dots promote odontogenic differentiation of stem cells from apical papilla via Wnt/β-catenin pathway activation.
Abstract
Objective
This study aimed to evaluate the biocompatibility of graphene oxide quantum dots (GOQDs) with stem cells from the apical papilla (SCAPs), determine the optimal concentration for promoting odontogenic differentiation by SCAPs and elucidate the underlying molecular mechanisms.
Methods
SCAPs were co-cultured with different GOQD concentrations (0.1-10 μg/mL) for subsequent experiments, while a broader concentration range (0.1-50 μg/mL) was used for CCK-8 biocompatibility screening. Cell proliferation and migration were assessed using CCK-8, live/dead staining and wound healing assays. Odontogenic differentiation was evaluated through ALP activity, Alizarin Red staining, qRT-PCR, and western blot analysis.
Results
GOQDs exhibited good biocompatibility with SCAPs and promoted proliferation and migration at low concentrations. The 0.1 μg/mL GOQD concentration optimally enhanced odontogenic differentiation, showing the highest ALP activity, increased mineralization, upregulation of odontogenic genes (RUNX2, OCN, DSPP, ALP), and increased expression of dentine-formation proteins (RUNX2, DSPP, DMP-1). Mechanistically, GOQDs increased nuclear β-catenin signal, and the pro-odontogenic effect was reversed by the Wnt inhibitor (DKK-1), suggesting that Wnt/β-catenin signaling is at least partly involved.
Conclusions
Low concentration GOQDs exhibit excellent biocompatibility with SCAPs and promote cell proliferation, migration and odontogenic differentiation. The optimal concentration for odontogenic differentiation is 0.1 μg/mL, at which GOQDs significantly upregulate the expression of odontogenic markers (RUNX2, ALP, DSPP, OCN, DMP‑1), suggesting that Wnt/β-catenin signaling is at least partly involved. CLINICAL
Significance
This in vitro study suggests that low concentration GOQDs may enhance odontogenic differentiation of SCAPs, supporting further investigation of GOQDs in regenerative endodontics. However, in vivo validation and long-term biosafety assessment are required before any clinical application can be considered.