Directional Migration and Odontogenic Differentiation of Bone Marrow Stem Cells Induced by Dentin Coated with Nanobioactive Glass

Introduction: This study aimed to use nanobioactive glass (nBG) to guide the directional migration of stem cells and odontogenic differentiation on primary dentin, which are important for the functional regeneration of pulp-dentin tissue. Methods: Human bone marrow stem cells (BMSCs) were cocultured with 0,5 mg/mL nBG. The cell-biomaterial interaction was monitored using the IncuCyte S3 live cell imaging system (Essen BioScience, Ann Arbor, MI). The adhesion and morphology of BMSCs growing on nBG-coated dentin were assessed at 2 hours and 3 days. The chemotaxis effect of nBG-coated dentin on BMSCs was tested using a 3-dimensional collagen gel model. Subcutaneous transplantation of nBG-treated dentin slices into nude mice was used to investigate cell homing and odontogenic differentiation in vivo. Results: nBG particles showed good biocompatibility, and they were gradually degraded and relocated during interactions with BMSCs. BMSCs had better initial attachment to an nBGcoated dentin surface than to an untreated dentin surface. Cell migration assays showed that nBG-coated dentin induced significantly more cell migration than untreated dentin. An in vivo study revealed that nBG-coated dentin slices facilitated recellularization and revascularization in the root canal and that dentin sialophosphoprotein-positive cells were detected on the surface of the primary dentin. Conclusions: nBG recruits stem cells to move toward dentin and further promotes cell adhesion and odontogenic differentiation on primary dentin, which help regenerate the biomimetic structure of pulp-dentin tissue.