Bp-Containing Injectable Piezoelectric GMA-SF Hydrogel Promotes Dentin Regeneration

To address the poor handling and slow setting of conventional pulp-capping materials, we developed an injectable piezoelectric GMA-SF hydrogel incorporated with black phosphorus nanofibers that, utilizes physiological mechanical stimuli from speaking and chewing to generate an electroactive microenvironment promoting dentin tissue regeneration. The piezoelectric GMA-SF/BP hydrogel was synthesized by incorporating black phosphorus-loaded coaxial electrospun into GMA-SF hydrogel. The study analyzed material morphology and BP dispersion using SEM/TEM, confirmed BP incorporation through EDS, verified chemical bonding by FT-IR.In Vitro, The study assess the biocompatibility of piezoelectric hydrogels with dental pulp stem cells using CCK-8 and LIVE/DEAD assay. Immunofluorescence and Western blot confirmed odontogenic protein expression (DSPP, DMP-1, ALP, RUNX2, OPN), while RNA-seq with Western blot validation revealed activated signaling pathway. In Vivo, a rat pulp-capping model was established with GMA-SF/BP hydrogel implantation (iRoot-BP as positive control). After 4 weeks, reparative dentin formation was evaluated by micro-CT and H&E staining, while immunohistochemistry assessed odontogenic marker expression. The GMA-SF/BP group exhibited: comparable viability to control, enhanced DSPP/OPN expression (IF), upregulated odontogenic markers (WB), and modulated Noggin-BMP/P-Smad1 axis. In Vivo, Micro-CT, H&E, and IHC demonstrated that the piezoelectric GMA-SF/BP hydrogel induced in situ dentin tissue regeneration effectively. This study illustrates that piezoelectric GMA-SF/BP hydrogel offering a novel strategy for dentin tissue regeneration.