Scap-Exo-Mediated Dspp Mrna Delivery Induces Bmmscs Specific Dentinogenesis

To investigate the use of exosomes derived from stem cells from apical papilla (SCAP-Exo) to deliver dentin sialophosphoprotein (DSPP) mRNA, promoting odontogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs) and facilitating tubular dentin regeneration in regenerative endodontic procedures. SCAP-Exo-mediated DSPP mRNA delivery systems (DSPP/SCAP-Exo) were synthesized via direct transfection, and were characterized using TEM, NTA, and Western blot analysis. Cy3-labeled DSPP mRNA was delivered into BMMSCs via SCAP-Exo, with intracellular uptake and release monitored in live-cell fluorescence imaging. Proteomic analysis of SCAP-Exo contents was performed to evaluate their effects on mRNA delivery efficiency and translation. Subsequently, the specific dentinogenesis of BMMSCs induced by DSPP/SCAP-Exo was asessed through PCR, Western blot and Alizarin Red staining. Finally, an in vivo subcutaneous implantation of tooth root fragments in nude mice was conducted to assess the effect of DSPP/SCAP-Exo on tubular dentin regeneration. SCAP-Exo effectively delivered mRNA into the cytoplasm, bypassing lysosomal degradation, enhancing transfection efficiency, and facilitating mRNA translation. The DSPP/SCAP-Exo system successfully delivered DSPP mRNA into BMMSCs, leading to the synthesis and secretion of DSPP protein and inducing specific odontogenic differentiation. Furthermore, DSPP/SCAP-Exo significantly promoted tubular dentin regeneration within tooth root fragments implanted subcutaneously in nude mice. The engineered DSPP/SCAP-Exo system could provide a valuable and feasible strategy for tubular dentin regeneration in regenerative endodontic procedures. SCAP-Exo might be used as a promising mRNA delivery platform for clinical tissue regeneration.