Bahman Nasiri-Tabrizi

Different ultra-lightweight carbon nanostructures with superb mechanical properties have made them attractive materials for reinforcing nanocomposites. However, the preparation of an ideal bone reinforcement is still a challenging task. Therefore, in the present study, a simple wet chemistry method was employed to synthesize silver nanoparticles (AgNPs) decorated graphene oxide (GO) nanocomposite as potential reinforcement in orthopedic applications. A well-dispersed nearly oval-shaped AgNPs with the mean size of 9 ± 6 nm were homogeneously formed on the surface of GO due to its supporting role in preventing agglomeration of fine particles. The results of the antibacterial activities revealed that the anchor of AgNPs on the surface of GO improved its antibacterial properties, in which the composite structure exhibited higher antibacterial activity against Escherichia coli (E. coli) than Staphylococcus aureus (S. aureus) bacteria. The proposed protocol can keep steady the scattering of the AgNPs in nanocomposite and prolong the antibacterial activity of the system.

The effectiveness of magnesium (Mg) alloys to improve the capability of bone tissue generation may be severely diminished if the required mechanical properties are not provided. Here, the effort is directed to model the mechanical performance of severely plastically deformed biodegradable ZK60 Mg alloy in bone regeneration protocols. For this purpose, the effects of parallel tubular channel angular pressing (PTCAP) on yield strength (σ YS ), ultimate tensile strength (σ UTS ), and elongation to failure (δ) were addressed. Given the multifaceted variables of the PTCAP with nonlinear interactions, a precise determination of the mechanical properties requires a large number of experiments. Therefore, gene expression programming (GEP) and genetic programming (GP) models were proposed to achieve appropriate combinations of mechanical properties for bone implant purposes based on a rational hypothesis that for correlation coefficient (|R|) higher than 0.8, a strong correlation is established between the predicted and measured values. The results verified that the highest mechanical performance was achieved at the second pass of PTCAP, thus has a great potential to be the most promising candidate for biodegradable implant material. Besides, the proposed models were capable of precisely predicting the mechanical performance of the SPD-processed biodegradable ZK60 Mg.