OR04 - Biocompatibility and Bioactivity of a Novel Piezoelectric Hydrogel as a Pulp Capping Material: An In Vitro Study

Pulp capping aims to facilitate the healing of injured pulp by using bioactive materials to ensure the formation of mineralized tissue or dentin bridge.

Objective: This study introduces an injectable bioactive piezoelectric hydrogel, PiezoGEL, created by combining gelatin methacryloyl (GelMA) with piezoelectric fillers of barium titanate. PiezoGEL generates electrical charges in response to biomechanical vibrations, enabling its therapeutic potential.

Methods: The effect of PiezoGEL on human dental pulp stem cells was evaluated through cell viability, mineralization, and gene expression analyses. Cell viability was assessed using the AlamarBlue assay, mineralization was measured with Alizarin Red staining, and expression of key odontogenic markers, including DSPP, DMP1, ALP, and COL1A1, were evaluated by qRT-PCR. One-way ANOVA was used to analyze the difference among groups.

Results: PiezoGEL demonstrated significant enhanced cell viability after stimulated with masticatory loading by day 10 compared to control. Also, PiezoGEL initiated mineralization earlier with higher levels as evidenced by increased ALP activity on days 5 and 10. DSPP expression was significantly upregulated for PiezoGEL under static conditions on day 10, and DMP1 expression peaked for PiezoGEL under cyclic loading on day 10.

Conclusion: We successfully developed an injectable piezoelectric hydrogel for direct pulp capping. PiezoGEL promoted cell viability, mineralization and upregulated the expression of genes related to dentin regeneration. These findings suggest that PiezoGEL exhibits superior biocompatibility and bioactivity compared to Biodentine, making it a promising alternative for pulp capping.