Exosome-loaded human amniotic membrane hydrogel modulates regenerative responses of human dental pulp stem cells.

Abstract

Context: Human dental pulp stem cell (hDPSC)-derived exosomes may support dentin-pulp regeneration, but free exosomes have limited local retention. Human amniotic membrane hydrogel may serve as a scaffold for exosome delivery.

Aim: This study evaluated the effect of exosome-loaded human amniotic membrane (hAM-Exo) hydrogel on hDPSC responses compared with free exosomes under basal and lipopolysaccharide (LPS)-stimulated conditions.

Materials and methods: hDPSCs were treated with free exosomes or hAM-Exo at 0.5%, 1%, and 5%, with or without LPS. Viability, cytocompatibility, migration, vascular endothelial growth factor-A (VEGF-A) secretion, and dentin sialophosphoprotein (DSPP) expression were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, live/dead, scratch, and enzyme-linked immunosorbent assay (ELISA) assays. Data were analyzed using two-way analysis of variance and post hoc tests.

Results: hAM-Exo was cytocompatible in all groups and showed a more stable metabolic profile than free exosomes at 96 h. hAM-Exo 1% significantly increased VEGF-A secretion under basal conditions at 48 h. Under LPS stimulation, hAM-Exo better preserved VEGF-A secretion than free exosomes, while hAM-Exo at all concentrations significantly enhanced DSPP expression on days 7 and 14.

Conclusions: hAM-Exo modulated regenerative-related hDPSC responses under basal and inflammatory conditions compared with free exosomes, supporting scaffold-assisted exosome delivery for cell-free regenerative endodontics.