Periodontal Ligament Stem Cell-Derived Small Extracellular Vesicles Embedded in Matrigel Enhance Bone Repair Through the Adenosine Receptor Signaling Pathway

Abstract

Bingjiao Zhao,1,2 Qingqing Chen,2 Liru Zhao,3 Jiaqi Mao,3 Wei Huang,2 Xinxin Han,2 Yuehua Liu1,2 1Department of Orthodontics, Shanghai Stomatological Hospital, Fudan University, Shanghai, 200001, People’s Republic of China; 2Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, 200001, People’s Republic of China; 3Department of Orthodontics, School of Stomatology, Hebei Medical University, Shijiazhuang, 050017, People’s Republic of ChinaCorrespondence: Yuehua LiuDepartment of Orthodontics, Shanghai Stomatological Hospital, Fudan University, 356 East Beijing Road, Shanghai, 200001, People’s Republic of China, Tel [phone], Fax [phone], Email [email protected]: Small extracellular vesicles (sEVs) are natural biocarriers for biomolecule transfer between cells and promising therapeutic strategies for bone defect repair. In this study, human periodontal ligament stem cell (PDLSC)-derived sEVs (P-EVs) were immobilized in Matrigel to establish a topical cell-free transplantation strategy for bone repair.Methods: PDLSCs were cultured and P-EVs were isolated from the culture supernatant. In a rat bilateral calvarial defect model, P-EV/Matrigel was plugged into one defect and PBS/Matrigel was applied to the other. Bone repair in vivo was assessed by micro-computed tomography, histomorphometry, and immunohistochemical staining. In vitro, we investigated the effects of P-EVs on the proliferation and migration capabilities of bone marrow mesenchymal stem cells (BMMSCs) and explored the potential mechanism of action.Results: The in vivo study showed that P-EV/Matrigel accelerated bone tissue repair by increasing cell infiltration when compared with the control. In vitro, P-EVs enhanced proliferation and migration of BMMSCs via increased phosphorylation of AKT and extracellular signal-regulated kinase 1/2 (ERK1/2). The role of P-EV-induced adenosine receptor signaling in AKT and ERK1/2 phosphorylation was a key mediator during enhanced BMMSC migration.Conclusion: These results are the first to demonstrate that P-EVs accelerated the repair of bone defects, partially through promoting cell proliferation and migration. P-EV/Matrigel, which combines topical EV-implantation and extracellular matrix scaffolds, provides a new cell-free strategy for bone tissue repair.Keywords: small extracellular vesicles, periodontal ligament stem cells, osteogenesis, cell-free therapy, bone defects

Keywords

• small extracellular vesicles
• periodontal ligament stem cells
• osteogenesis
• cell-free therapy
• bone defects