BMSC-Exosomes Carry Mutant HIF-1α for Improving Angiogenesis and Osteogenesis in Critical-Sized Calvarial Defects

Abstract

Repair and reconstruction of critical-sized bone defects has always been a difficult task in orthopedics. Hypoxia inducible factor-1α (HIF-1α) plays an important role in bone defect repair, it has the dual function of promoting osteogenesis and vascular regeneration, but it is quickly degraded by the body under normoxic conditions. Previously we prepared mutant HIF-1α, which has been shown to efficiently maintain cellular expression under normoxic conditions. In this study, we evaluated for the first time the role of exosomes of rat bone marrow mesenchymal stem cell carry mutant HIF-1α (BMSC-Exos-HIF1α) in repairing critical-sized bone defects. Evaluation of the effects of BMSC-Exos-HIF1α on bone marrow mesenchymal stem cells (BMSCs) proliferation and osteogenic differentiation by cell proliferation assay, alkaline phosphatase activity assay, alizarin red staining, real-time quantitative polymerase chain reaction. BMSC-Exos-HIF1α was loaded onto the β-TCP stent implanted in the bone defect area using a rat cranial critical-sized bone defect model, and new bone formation and neovascularization were detected in vivo by micro-CT, fluorescence labeling analysis, Microfil perfusion, histology and immunohistochemical analysis. In vitro results showed that BMSC-Exos-HIF1α stimulated the proliferation of BMSCs and upregulated the expression level of bone-related genes, which was superior to bone marrow MSC exosomes (BMSC-Exos). In vivo results showed that BMSC-Exos-HIF1α combined with β-TCP scaffold promoted new bone regeneration and neovascularization in the bone defect area, and the effect was better than that of BMSC-Exos combined with β-TCP scaffold. In this study, the results showed that BMSC-Exos-HIF1α stimulated the proliferation and osteogenic differentiation of BMSCs and that BMSC-Exos-HIF1α combined with β-TCP scaffolds could repair critical-sized bone defects by promoting new bone regeneration and neovascularization.

Exosomes derived from pioglitazone-pretreated MSCs accelerate diabetic wound healing through enhancing angiogenesis

“…Recent research has reported that exosomes derived from MSCs have cardioprotective effects by inhibiting cardiomyocyte apoptotic injury [ 25 ]. BMSCs-derived exosomes have been shown to stimulate the proliferation and osteogenic differentiation of BMSCs to promote new bone regeneration and neovascularization in bone defects [ 26 ]. Therefore, exosomes are a cell-free therapeutic that may be safer than direct MSCs therapy and provide a potential modality for tissue regeneration [ 27 , 28 ].…”

Technological Advances of 3D Scaffold-Based Stem Cell/Exosome Therapy in Tissues and Organs

“…Natural materials include collagen ( Chang et al, 2011 ), gelatin ( Chang et al, 2020 ), fibrin ( Rabbani et al, 2017 ), silk fibroin ( Qing et al, 2018 ), alginate ( Yang et al, 2018 ), gellan gum, hyaluronic acid (HA) ( Yazdani et al, 2019 ), chitosan ( Kim et al, 2016 ), Matrigel ( Wang et al, 2020b ); while synthetic polymer materials include poly caprolactone (PCL) ( Zhang et al, 2017 ), polydimethylsiloxane (PDMS) ( McKee et al, 2017 ), polyethylene oxide (PEO) ( Evrova et al, 2016 ), polylactic acid (PLA) ( Gandolfi et al, 2020 ), poly lactic acid-glycolic acid (PLGA) ( Swanson et al, 2020 ), polyvinyl alcohol (PVA) ( Kalachaveedu et al, 2020 ), polyethylene glycol (PEG), tribasic calcium phosphate (TCP) ( Ying et al, 2020 ). Biomaterials used for 3D bioprinting are called “bio-inks.”…”

“… Yang et al (2020b) reported that the combination of UCMSC-derived exosomes and HAP-embedded crosslinked HA-alginate hydrogel in situ significantly enhanced bone regeneration of preosteoblasts. Several studies Qi et al (2016) ; Zhang et al (2016) , and Ying et al (2020) reported that the combination of iPSC- or MSC-derived exosomes and a β-TCP scaffold promoted angiogenesis and osteogenesis. Three studies Sanchez et al (2020) ; Wang et al (2020d) , and Zha et al (2021) reported that the combination of exosomes and a PCL scaffold significantly enhanced osteogenic differentiation of MSCs.…”

Current Application of Beta-Tricalcium Phosphate in Bone Repair and Its Mechanism to Regulate Osteogenesis

“…The incorporation of exosomes derived from bone mesenchymal stem cells (BMSC) and hypoxia inducible factor-1α (HIF-1α) to β-TCP scaffolds significantly repaired rat criticalsized bone defects by facilitating new bone regeneration and neovascularization (Ying et al, 2020). Dental pulp stem cells (DPSCs)-derived extracellular vesicle (EVs)/β-TCP scaffolds was demonstrated to boost bone formation in the periphery of the defects (Imanishi et al, 2021).…”