Layered-graphene reinforced-metal matrix nanocomposites with excellent mechanical properties and low density are a new class of advanced materials for a broad range of applications. A facile three-step approach based on ultra-sonication for dispersion of graphene nanosheets (GNSs), ball milling for Al-powder mixing with different weight percentages of GNSs, and equal-channel angular pressing for powders’ consolidation at 200 °C was applied for nanocomposite fabrication. The Raman analysis revealed that the GNSs in the sample with 0.25 wt.% GNSs were exfoliated by the creation of some defects and disordering. X-ray diffraction and microstructural analysis confirmed that the interaction of the GNSs and the matrix was almost mechanical, interfacial bonding. The density test demonstrated that all samples except the 1 wt.% GNSs were fully densified due to the formation of microvoids, which were observed in the scanning electron microscope analysis. Investigation of the mechanical properties showed that by using Al powders with commercial purity, the 0.25 wt.% GNS sample possessed the maximum hardness, ultimate shear strength, and uniform normal displacement in comparison with the other samples. The highest mechanical properties were observed in the 0.25 wt.% GNSs composite, resulting from the embedding of exfoliated GNSs between Al powders, excellent mechanical bonding, and grain refinement. In contrast, agglomerated GNSs and the existence of microvoids caused deterioration of the mechanical properties in the 1 wt.% GNSs sample.

The field of neural tissue engineering has undergone a revolution due to advancements in 3D printing technology. This technology now enables the creation of intricate neural tissue constructs with precise geometries, topologies, and mechanical properties. Currently, there are various 3D printing techniques available, such as stereolithography and digital light processing, and a wide range of materials can be utilized, including hydrogels, biopolymers, and synthetic materials. Furthermore, the development of 4D printing has gained traction, allowing for the fabrication of structures that can change shape over time using techniques such as shape-memory polymers. These innovations have the potential to facilitate neural regeneration, drug screening, disease modeling, and hold tremendous promise for personalized diagnostics, precise therapeutic strategies against brain cancers. This review paper provides a comprehensive overview of the current state-of-the-art techniques and materials for 3D printing in neural tissue engineering and brain cancer. It focuses on the exciting possibilities that lie ahead, including the emerging field of 4D printing. Additionally, the paper discusses the potential applications of 5D and 6D printing, which integrate time and biological functions into the printing process, in the fields of neuroscience.

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Osteoarthritis is the second most common disorder after heart disease. This progressive degenerative disease affects the knee joint more than any others. The exact etiology of knee osteoarthritis is not clear, however, there are many predisposing factors such as obesity, age, gender, etc., that can increase the incidence and prevalence of this disease. Early diagnosis in knee osteoarthritis is very important. Despite the variety of diagnostic methods, lack of a valid and reliable diagnostic approach to detect the disorder in early stages has always been a challenge for researchers. Establishing an efficient therapeutic protocol for these patients is another crucial challenge. Recently, in addition to conventional treatments, which are surgical and non-surgical, tissue engineering and regenerative medicine as novel therapeutic modalities have received remarkable attention. In this paper, current diagnostic and therapeutic methods for knee osteoarthritis are discussed and potential biomarkers for early diagnosis and monitoring the clinical condition are discussed.