Biological Matrices Promote Odontoblastic Markers Expression in Stem Cells from Apical Papilla: An In Vitro Study

Odontoblastic differentiation is a cellular process that requires signaling molecules and extracellular matrix components provided by the dentin-pulp microenvironment. Several scaffolds have been proposed to induce odontoblast differentiation for pulp regeneration. This study evaluated the ability of collagen sponge and decellularized dental pulp, along with dentin, to promote the expression of odontoblastic markers in stem cells from the apical papilla (SCAPs).

Experimental groups consisted of 2 different biological matrices: (1) human decellularized dental pulp seeded with SCAP cells in the presence or absence of dentin discs (n = 3), and (2) commercial collagen sponge seeded with SCAP cells in the presence or absence of dentin discs (n = 3), and their respective controls (no seeded matrices). Cultures were placed on a dentin disc model and maintained in a 3-dimensional cell culture for 4 weeks. Thereafter, the samples were processed for histological analysis. Cell expression of odontoblastic markers was assessed on hematoxylin-eosin staining and immunohistochemistry using anti-dentin sialophosphoprotein (DSPP), anti-dentin matrix protein 1 (DMP1), and anti-alkaline phosphatase (ALPL) antibodies. Both qualitative and exploratory quantitative analysis were performed.

SCAPs cultured in the decellularized human dental pulp matrix and in the collagen sponge expressed DSPP, DMP1, and ALPL markers. Based on qualitative analysis and exploratory numerical data, the presence of dentin disc appeared to enhance DMP1 expression in the decellularized matrix and collagen sponge groups, while reducing ALPL levels in the decellularized matrix group.

Within the limitations of this study, both decellularized pulp scaffolds and collagen scaffolds supported odontoblastic marker expression in SCAPs. Considering its cost-effectiveness and widespread availability, commercial collagen may be considered a suitable scaffold for regenerative applications. However, further studies are required to confirm these findings.