Application of Dynamic Hydrogels for Dental Pulp Regeneration: A Comparative Study on Cellular Viability, Inflammatory Modulation, and Differentiation Potential

Abstract

Regenerative endodontics therapy aims to restore the pulp-dentin complex through biological approaches, yet current cell-free techniques often unable to achieve true dental pulp regeneration, resulting in fibrous tissue or calcification. This study investigates dynamic hydrogels as advanced scaffolds for dental pulp stem cell-mediated regeneration, leveraging their viscoelastic properties to optimize cell behavior and immune modulation. Dynamic hydrogels were synthesized using host-guest chemistry (GelMA/HA-Ada-CD-SH) to mimic the extracellular matrix’s dynamic mechanics, contrasting them with static non-dynamic GelMA hydrogels. Stem cells and macrophages were encapsulated in sterilized hydrogels to evaluate viability, inflammatory responses, and differentiation. Results demonstrated that dynamic hydrogels significantly enhanced dental pulp stem cells elongation and upregulated neural stemness markers (Nestin/Sox2 expression increased 2.5-fold). Mechanistically, dynamic hydrogels significantly suppressed pro-fibrotic TGF-β/SMAD signaling, while significantly promoting pro-regenerative inflammation, evidenced by NF-κB activation and VEGF-driven angiogenesis. Conversely, dynamic hydrogels reduced pathological inflammation markers in macrophages including iNOS. The findings reveal that dynamic hydrogels uniquely balance immune activity—attenuating fibrosis while transiently activating NF-κB to initiate repair—and enhance neural differentiation. Their stress-relaxation properties enabled stem cells remodeling, whereas non-dynamic hydrogels restricted cell spreading due to rigid networks. Despite these advances, limitations include short-term in vitro analysis and a limited cytokine panel. Future work should incorporate long-term immune profiling and clinical validation. In conclusion, dynamic hydrogels have potential to be used as a scaffold for regenerative endodontic therapy, due to its ability to suppress fibrosis, modulate inflammation, and promote neuro-vascular regeneration. By emulating native extracellular matrix dynamics, they address critical limitations of current materials, offering a clinically viable pathway to achieve functional pulp-dentin regeneration.