Hydrogel contained valproic acid accelerates bone-defect repair via activating Notch signaling pathway in ovariectomized rats

• Published in: Journal of materials science. Materials in medicine 2022-01, Vol.33 (1), p.4-4, Article 4
• Main Authors: Tao, Zhou-Shan, Li, Tian-Lin, Xu, Hong-Guang, Yang, Min
• Format: Article
• Language: English
• Subjects: Alizarin; Alkaline phosphatase; Animals; Biomaterials; Biomaterials Synthesis and Characterization; Biomechanical engineering; Biomechanics; Biomedical Engineering and Bioengineering; Biomedical materials; Blood vessels; Bone growth; Bone morphogenetic protein 2; Bone Regeneration - drug effects; Bone strength; Calcification, Physiologic - drug effects; Cells, Cultured; Ceramics; Chemistry and Materials Science; Composites; Computed tomography; Disease Models, Animal; Epiphysis; Female; Femur; Glass; Histology; Hydrogels; Hydrogels - chemistry; Hydrogels - pharmacology; Immunofluorescence; Materials Science; Mice; Mineralization; Natural Materials; Notch1 protein; Orthopaedic implants; Osteogenesis; Osteogenesis - drug effects; Osteoporosis - pathology; Osteoporosis - therapy; Ovariectomy; Polymer Sciences; Rats; Rats, Sprague-Dawley; Receptors, Notch - metabolism; Regeneration; Regeneration (physiology); Regenerative Medicine/Tissue Engineering; Repair; Signal transduction; Signal Transduction - drug effects; Signaling; Staining; Surfaces and Interfaces; Thin Films; Tissue Scaffolds - chemistry; Valproic acid; Valproic Acid - chemistry; Valproic Acid - pharmacology; Western blotting
• ISSN: 0957-4530; 1573-4838
• DOI: 10.1007/s10856-021-06627-2

The purpose was to observe whether valproic acid (VPA) has a positive effect on bone-defect repair via activating the Notch signaling pathway in an OVX rat model. The MC3T3-E1 cells were cocultured with VPA and induced to osteogenesis, and the osteogenic activity was observed by alkaline phosphatase (ALP) staining, Alizarin Red (RES) staining and Western blotting (WB). Then the hydrogel-containing VPA was implanted into the femoral epiphysis bone-defect model of ovariectomized (OVX) rats for 12 weeks. Micro-CT, biomechanical testing, histology, immunofluorescence, RT-qPCR, and WB analysis were used to observe the therapeutic effect and explore the possible mechanism. ALP and ARS staining and WB results show that the cell mineralization, osteogenic activity, and protein expression of ALP, OPN, RUNX-2, OC, Notch 1, HES1, HEY1, and JAG1 of VPA group is significantly higher than the control group. Micro-CT, biomechanical testing, histology, immunofluorescence, and RT-qPCR evaluation show that group VPA presented the stronger effect on bone strength, bone regeneration, bone mineralization, higher expression of VEGFA, BMP-2, ALP, OPN, RUNX-2, OC, Notch 1, HES1, HEY1, and JAG1 of VPA when compared with OVX group. Our current study demonstrated that local treatment with VPA could stimulate repair of femoral condyle defects, and these effects may be achieved by activating Notch signaling pathway and acceleration of blood vessel and bone formation.