Effects of Periodontal-Specific Exosomes and rhBMP2 on Osteogenic Behaviour and Differentiation of BMSCs

Growth factors, including recombinant human bone morphogenetic protein-2 (rhBMP2), have been clinically utilised for large bone augmentation with good outcomes. Nevertheless, long-term healing, swelling, safety concerns, and high cost limit their use. Exosomes, nanoscale extracellular vesicles, have emerged as promising regenerative alternatives. This study assessed the osteogenic potential of periodontal-specific exosomes (Px) on bone marrow mesenchymal stem cells (BMSCs) compared to rhBMP2. Px were morphologically characterised by TEM and quantified via BCA assay. BMSCs were treated with Px at 1:10, 1:50, and 1:100 dilutions (100, 20, and 10 μg/mL) and compared to rhBMP2 (100 ng/mL). Px uptake was evaluated using PKH26 labeling. Functional assays included viability, migration, alkaline phosphatase (ALP) activity, alizarin red (ARS) mineralization, collagen, osteocalcin secretion, and RT-PCR analysis of osteogenic genes. Px exhibited spheroidal to cup-shaped morphology and internalisation in BMSCs up to 18 days. Compared to rhBMP2, Px promoted viability (1.14-fold), migration (1.78-fold) up to 1.14 and 1.78-fold, ALP (1.48-, 4.11-fold), ARS (1.43-, 14.71-fold), collagen (1.40-, 3.58-fold), and osteocalcin (1.86-, 5.2-fold). Gene expression demonstrated significant upregulation of ALP (1.73-fold), RUNX2 (1.70-fold), OCN (1.36-fold), and OPN (1.35-fold). Overall, Px significantly enhanced BMSC osteogenesis compared to rhBMP2, highlighting their potential as a cell-free nanotherapeutic in bone tissue engineering.