Osteogenic Efficacy of Porous Glass Microspheres-Loaded Dental Pulp Stem Cell-Derived Exosomes for Orthobiologic Applications

Macromol Biosci. 2026 Jan;26(1):e00481. doi: 10.1002/mabi.202500481.

Abstract

The appropriate characteristics of carrier biomaterial must prevent rapid sequestration and clearance of exosomes. This study aims to investigate the efficacy of porous phosphate-based glass microspheres (PGMS) as carriers for human dental pulp stem cell (hDPSC)-derived exosomes in dental orthobiologic applications. PGMS (40P2O5-24MgO-16CaO-20Na2O) is prepared via flame spheroidization, characterized using SEM-EDS, XRD, and mercury intrusion porosimetry. hDPSC-Exosomes (Exo) are extracted, labeled with DiL, and verified by confocal and flow cytometry. Cell viability is assessed whereby hDPSCs are exposed to 1 mg/mL PGMS, or 10 µg/mL Exo, or 1 mg/mL PGMS loaded with 10 µg/mL Exo. Osteogenic potential is assessed by ALP assay, qPCR, western blotting, and alizarin staining. PGMS exhibits 75% interconnected pores, and XRD shows broad halo peak within the 2θ range of 20°-40°. Exo are CD9+, CD63+, and CD81+, and their cellular uptake is enhanced by 24 h. PGMS supports continued hDPSC proliferation. Exo-alone boosts hDPSC proliferation (24 h) and PGMS+Exo shows a similar rise. Exo-alone and PGMS+Exo significantly upregulate bone markers, while PGMS+Exo significantly upregulates Col1, ALP, and increases nodule formation. Western blotting shows an increase in BMP7, Col1, and OC in Exo-alone and PGMS+Exo. PGMS retains Exo, protects its functionality and release for favorable osteogenesis, offering a promising strategy as an exosome carrier in orthobiologic applications.

Keywords: dental pulp stem cells; exosome carrier and osteogenic potential; exosomes; porous glass microspheres.

MeSH terms

  • Cell Differentiation / drug effects
  • Cell Survival / drug effects
  • Dental Pulp* / cytology
  • Dental Pulp* / metabolism
  • Exosomes* / chemistry
  • Exosomes* / metabolism
  • Glass* / chemistry
  • Humans
  • Microspheres*
  • Osteogenesis* / drug effects
  • Porosity
  • Stem Cells* / cytology
  • Stem Cells* / metabolism