TiO₂-Induced In Situ Reaction in Graphene Oxide-Reinforced AZ61 Biocomposites to Enhance the Interfacial Bonding

Abstract

Graphene oxide (GO) can improve the degradation resistance of biomedical Mg alloy because of its excellent impermeability and outstanding chemical inertness. However, the weak interfacial bonding between GO and Mg matrix leads to easily detaching during degradation. In this study, in situ reaction induced by TiO 2 took place in the AZ61−GO biocomposite to enhance the interfacial bonding between GO and Mg matrix. For the specific process, TiO 2 was uniformly and tightly deposited onto the GO surface by hydrothermal reaction (TiO 2 /GO) first and then used for fabricating AZ61−TiO 2 /GO biocomposites by selective laser melting (SLM). Results showed that TiO 2 was in situ reduced by magnesiothermic reaction during SLM process, and the reduzate Ti, on the one hand, reacted with Al in the AZ61 matrix to form TiAl 2 and, on the other hand, reacted with GO to form TiC at the AZ61−GO interface. Owing to the enhanced interfacial bonding, the AZ61−TiO 2 /GO biocomposite showed 12.5% decrease in degradation rate and 10.1% increase in compressive strength as compared with the AZ61−GO biocomposite. Moreover, the AZ61− TiO 2 /GO biocomposite also showed good cytocompatibility because of the slowed degradation. These findings may provide guidance for the interfacial enhancement in GO/metal composites for biomedical applications.

Accelerated degradation of HAP/PLLA bone scaffold by PGA blending facilitates bioactivity and osteoconductivity

“…Each specimen was submerged in a 15-ml centrifuge tube that contained 10 ml PBS solution, and the tubes were maintained at 37 °C in an incubator. After being incubated for various time duration (7, 14, 21 and 28 d), the specimens were taken out from the solution, rinsed with distilled water, and dried in a vacuum oven at 40 °C for 12 h. The weight loss was calculated by the following equation [ 28 ]: weight loss =( W 0 - W 1 )/ W 0 × 100%, where W 0 and W t were the original weight and the weight of the specimen after immersing in PBS up to day t , respectively. The pH of the degradation solution was measured once 7 d for 28 d. The morphologies of the specimens after degradation at different time intervals were studied using SEM.…”

Advances in biocermets for bone implant applications

“…Generally, the degree of interface reaction and the formation of interface products have a great influence on the microstructure and properties of the biocermets. Appropriate interface products can improve the wettability and form a strong chemical bonding between the reinforcement and matrix [165].…”

Micro Magnetic Field Produced by Fe3O4 Nanoparticles in Bone Scaffold for Enhancing Cellular Activity

“…However, when the Fe 3 O 4 content was further increased to 9% (Figure 5f), obvious agglomeration began to appear in the scaffold. Usually, on the premise of uniform dispersion, the more the amount of nanoparticles added, the better the enhancing effect [41]. When the Fe3O4 content was less than or equal to 7%, the uniformly dispersed Fe3O4 nanoparticles acted as a nanoscale reinforcement in the polymer matrix and reached a peak at 7%.…”