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Bone fractures/defects are normal in more established individuals experiencing osteoporosis. In this work, we have explored osteoblast bond, multiplication, and separation on biocomposites of bioactive dual minerals substituted hydroxyapatite/alginate-chitosan/graphene oxide porous biocomposites coated magnesium alloy (AZ91 Mg alloy). Hydroxyapatite is one the most important mineral constituents for bony which, due to its bioactive and histocompatible properties, is commonly used as a material for hard tissue substitution. However, the use of apatite as hard tissue implants is restricted due to its fragile nature and reduced mechanical properties. To overcome this defect and to generate suitable bone implant material, dual minerals substituted hydroxyapatite (DM-HAP) is combined with biodegradable polymer alginate-chitosan (ALG-CS). Graphene oxide (GO) is integrated into the biocomposite, which has long been believed for soft and hard tissue implants owing to its excellent structural and mechanical properties, to enhance the mechanical properties of the biocomposite. Graphene oxide grounds are most important for the reconstruction of bone; new, outstanding DM-HAP/ALG-CS/GO scaffold on Mg alloy has been developed. As developed coatings were characterized by X-ray diffraction (XRD) and scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDX). Besides, the mechanical strength of the coating has also been assessed using adhesion and Vickers micro-hardness tests. In furtherer, the antibacterial activity of the composite was studied against Staphylococcus aureus and Escherichia coli and cell viability were observed in vitro against osteoblast cells and in vivo in rats. As a result, the results obtained propose that DM-HAP/ALG-CS/GO biocomposite can be believed as a prospective applicant for biomedical applications.

Bone morphogenetic protein 9 (BMP9), also known as growth differentiation factor 2, plays a key role in promoting osteosarcoma growth. However, the underlying mechanism remains to be determined. The aim of the present study was to determine the mechanism of BMP9 promoting the growth of osteosarcoma mediated by the Notch signaling pathway. Osteosarcoma cell lines, 143B and MG63, were used for the in vitro experiments. Cell proliferation, cell migration and cell cycle transformation were monitored under various settings. The control and experimental groups used in the present study were BMP9 adenovirus (AdBMP9), a recombinant adenovirus expressing the dominant-negative mutant of Notch1 (AdR-dnNotch1), AdBMP9+AdR-dnNotch1 and AdBMP9+compound E (blocker of the Notch signaling pathway). The results showed that Notch ligands DLL1, JAG1 and JAG2, as well as Notch receptors Notch1, Notch2 and Notch3 were markedly expressed in the two cell lines. Cell proliferation and migration ability increased in the AdBMP9 group and were higher than that in the AdBMP9+AdR-dn Notch1 and AdBMP9+compound E group. Cell proliferation and migration in the AdR-dnNothc1 group was lower than that in the AdBMP9 group, although the differences were not statistically significant (P>0.05). The cell cycle ratio in the S/G2 phase increased significantly in the AdBMP9 group and was higher than that in the AdBMP9+AdR-dnNotch1 and AdBMP9+compound E groups. By contrast, the ratio of the cell cycle in S/G2 phase in the AdR-dnNotch1 group was lower than that in the AdBMP9 group. The differences were not statistically significant (P>0.05). In conclusion, the results showed that the Notch signaling pathway plays an important role in mediating the growth of osteosarcoma promoted by BMP9.