Pulp-dentin regeneration in the apical region of immature permanent teeth represents a significant clinical challenge. Tissue engineering approaches using bioactive molecules and scaffolds may have the potential to regenerate the natural apical structure of these teeth, representing a superior alternative to existing treatment regimens. The aims of this study are (i) to evaluate the VitroGel 3D system, an animal origin-free polysaccharide hydrogel, as a possible injectable scaffold for pulp-dentin regeneration and (ii) to investigate the effects of stromal cell-derived factor-1α (SDF-1α) and bone morphogenetic protein-2(BMP-2) cotreatment on odontogenic differentiation of human stem cells from apical papilla (SCAP) cultured in the VitroGel 3D system. The morphology, viability and proliferation of SCAP cultured in the VitroGel 3D system were measured via scanning electron microscopy (SEM), live and dead cell staining and CCK-8 assays. Alkaline phosphatase (ALP) activity, real-time reverse transcriptase polymerase chain reaction (real-time RT-PCR) and Western blot analysis were further used to evaluate the odontogenic differentiation of SCAP cultured in the VitroGel 3D system in vitro. Finally, the odontogenic differentiation was assessed in vivo through ectopic subcutaneous injection. The results showed that SCAP cultured in 3D hydrogel demonstrated favorable viability and proliferation. SDF-1α and BMP-2 cotreatment enhanced odontogenic differentiation-related gene and protein expression in vitro and promoted odontogenic differentiation of SCAP in vivo. In conclusion, the present study demonstrated that the VitroGel 3D system promoted SCAP proliferation and differentiation. Moreover, SDF-1α cotreatment had synergistic effects on BMP-2-induced odontogenic differentiation of human SCAP cultured in the VitroGel 3D system both in vitro and in vivo.
Keywords: Bone morphogenetic protein-2; Hydrogel; Odontoblastic differentiation; Stem cells from apical papilla; Stromal cell-derived factor-1α.