(PR009) Development of a Photocrosslinkable Hydrogel for Regenerative Endodontic Therapy.

Introduction: The treatment of pulpitis and pulp necrosis often leads to the loss of vitality in the affected tooth. Regenerative endodontic therapy (RET) offers a promising approach to extend the lifespan of immature permanent teeth by promoting revitalization and enabling continued root development. This study focuses on developing an acellular drug-free photocrosslinkable hydrogel, utilizing Gelatin Methacrylate (GelMA) and Heparan sulfate (HS) to promote Dentin-Pulp Complex (DPC) regeneration and continues tooth growth.

Methods: The hydrogel fabrication involved GelMA and HS, with swelling tests indicating optimal properties for dentinal wall adaptability. In vitro cellular experiments were performed utilizing a mitochondrial respiration assay, Alizarin Red Staining, and Alkaline Phosphatase Activity in periodontal ligament stem cells (PDLSCs) cultured on GelMA/Hep hydrogel. In vivo studies in canine models with open apices (immature tooth) were performed to evaluate the pulp-like tissue formation, regenerative dentin formation, and vascularization in the hydrogel group compared to nonvital (Apexification) and RET (Revascularization).

Results: Swelling behavior analysis indicated superior adaptability of GelMA/Hep hydrogel to dentinal walls. In vitro, studies showed cytocompatibility and mineralization induction in treated cells with a hydrogel group. In vivo studies demonstrated successful pulp-like tissue formation, apex closure, and regenerative dentin formation in hydrogel-treated teeth.

Conclusion: This injectable hydrogel, incorporating GelMA and Heparin, proves promising for dentin-pulp complex regeneration. Further research and clinical trials are warranted to validate and translate these findings into effective dental pulp regeneration therapies.