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

TL;DR

This study compares periodontal exosomes and a bone growth protein to see which better helps bone stem cells grow and differentiate.

Contribution

The study demonstrates that periodontal exosomes outperform rhBMP2 in promoting osteogenic activity in BMSCs.

Findings

Periodontal exosomes significantly enhanced BMSC viability, migration, and osteogenic markers compared to rhBMP2.

Exosome-treated BMSCs showed higher mineralization and collagen production than cells treated with rhBMP2.

Periodontal exosomes upregulated key osteogenic genes like ALP, RUNX2, OCN, and OPN more effectively than rhBMP2.

Abstract

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.

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