Ex Vivo Modeling of Multidomain Peptide Hydrogels with Intact Dental Pulp

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Dental Research

Background:

• Preserving vital dental pulp is crucial in restorative dentistry.
• Tissue engineering scaffolds are being developed for pulp capping to stimulate dentin formation.
• Previous in vitro studies showed multidomain peptide (MDP) hydrogel biocompatibility with dental pulp cells.

Purpose of the Study:

• To evaluate the biocompatibility and bioactivity of MDP hydrogel scaffolds in an ex vivo whole-organ dental pulp model.
• To assess the impact of MDP scaffold placement (pulp core vs. odontoblast interface) on tissue architecture, odontoblast function, and mineralization.

Main Methods:

• Utilized an established ex vivo mandible organ culture model.
• Injected MDP hydrogel scaffolds into the pulp core or at the odontoblast-dentin interface.
• Cultured slices for up to 10 days, followed by histological, Alizarin red staining, and immunohistochemical analyses.

Main Results:

• MDP scaffolds showed minimal disruption to pulp tissue architecture in both central and peripheral placements.
• Odontoblast layer integrity was preserved when scaffolds were placed at the odontoblast-dentin interface.
• Mineralization and dentin sialophosphoprotein deposition by odontoblasts occurred around peripherally placed scaffolds, indicating sustained function.
• Centrally placed scaffolds showed matrix metalloproteinase 2 expression, suggesting degradation, and lacked mineralization or significant odontoblast response.

Conclusions:

• MDP hydrogel scaffolds are biocompatible within whole dental pulp tissue, preserving local architecture.
• Placing MDP scaffolds at the dentin-odontoblast interface sustains odontoblast function and pulp vitality.
• These findings support the potential of MDP hydrogels as effective pulp-capping agents in restorative dentistry.