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

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 (40P 2 O 5 ‐24MgO‐16CaO‐20Na 2 O) 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.