Biodegradable Mg alloys are becoming increasingly popular as potential metallic biomaterials for vascular and orthopedic temporary implants due to their favorable mechanical, electrochemical and biological properties. Nevertheless, several challenges persist with Mg scaffolds, including high degradability, inadequate mechanical properties, and intricate manufacturing processes. Processing and alloying are pivotal methods for the improvement of the properties of Mg alloys for use in biomedical applications. The focus of this study is on the process technology for the fabrication of ultra-precise geometries and the achievement of the mechanical and degradation properties for biodegradable vascular stents. To this end, a two-step extrusion process has been developed to fabricate microtubes. The present study investigates the effect of extrusion ratio on the room-temperature tensile properties and vitro degradation behavior of microtubes for two Mg alloys in terms of microstructure and texture.

Degradable metals such as magnesium and magnesium alloys offer advantages such as high specific strength, low elastic modulus, and excellent biocompatibility, making them highly promising for applications in orthopedic and dental hard tissue repair, including bone plates, bone screws, and oral barrier membranes. However, key challenges hindering the use of high-purity magnesium (HCP structure) in biomedical and industrial applications include insufficient strength and toughness, poor room-temperature formability, and a high degradation rate. This paper focuses on the processing of high-purity magnesium (HP Mg, 99.99 wt%) metal materials, the development of high-purity magnesium bone screws and corresponding surface protective coatings, and the invention of a composite strengthening technique based on "warm extrusion–cold rotary swaging." Additionally, various high-performance protective coatings for magnesium-based metal surfaces have been designed and developed. Finally, potential future applications of magnesium and magnesium alloys in orthopedic and dental medical fields are proposed.

Micro Arc Oxidation (MAO) coating has long been explored in regards to biometals. However, relatively little discussion in reports on MAO coating of biometals has been given to the role that the power supply plays in determining the size of the device, or more specifically its surface area, that can be coated. In this report we discuss the role that the power supply’s current capacity and constancy play in determining the maximum surface area that can be coated as well as the relationship of these criteria to power supply price.

Previous work indicated that long-period stacking ordered (LPSO) phase and/or γ in rare earth containing Mg alloys had contradictory mechanisms responsible for their degradation in less complex or standard salt media, such as 0.9% NaCl solution. They needed to be further investigated in a more realistic simulated body fluid (SBF). The present work investigated the influence of the amount and types of intermetallics on the degradation behavior of as-cast and extruded Mg-xDy-Zn (x = 5, 10, 15 wt. %) alloys using immersion test in DMEM+10% FBS under cell culture conditions. It was revealed that the existence of intermetallics exhibited different effects on the degradation behavior of as-cast alloys. The degradation rate of Mg-5Dy-1.5Zn alloy consistently increased because of the scattered distribution of few intermetallics (W, γ and 18R LPSO). In contrast, though the volume fraction of intermetallics in Mg-10Dy-1.5Zn and Mg-15Dy-1.5Zn alloys are larger than Mg-5Dy-1.5Zn alloys, the continuous network structure of intermetallics (γ and 18R LPSO) and a compact degradation layer provided protection from further degradation for these two alloys, thus resulting in the lower degradation rate compared to the Mg-5Dy-1.5Zn alloy. In extruded with a 48h preheating treatment alloys, the volume fraction of intermetallics increased with the addition of Dy content. However, attributed to the high volta potential of W phase which led to the severe galvanic corrosion, Mg-5Dy-1.5Zn alloy showed the highest degradation rate among three extruded alloys. Meanwhile, the W phase in Mg-10Dy-1.5Zn alloy did not trigger severe local corrosion could be attributed to the denser compact degradation layer on the surface of γ phase, which retard the corrosive ions for further penetration to Mg matrix. In addition, such dense γ phase could act as cathode that accelerates the degradation of Mg matrix, therefore Mg-10Dy-1.5Zn exhibited a higher degradation rate than Mg-15Dy-1.5Zn alloy.

We report here on an in vitro degradation study of what is currently considered to be the optimal OSU Mg alloy, Mg1.6Zn0.5Ca0.5Mn, for skeletal fixation hardware. In this study our goal is to sufficiently prevent degradation of this material such that its mechanical properties do not degrade below what would be needed to fixate healing bones for at least 2 months. The enhancement gained from the use of this alloy and heat treatment is not sufficient. Here we report promising results from the addition of a two-step coating process: (a) coating with Micro-Arc Oxidation followed by (b) 15-50 layers of sol gel sealing with TiO2 and entrapped HAP/β-TCP nanoparticles.

Stronger absorbable wire materials with good degradation profiles can enable valuable new interventions, especially in small vascular anatomies where relative device downsizing is important. Strength levels beyond 2 GPa are a critical ingredient to success in many medical interventions requiring thin gage wire elements. As example, stainless steel with strength exceeding 2.9 GPa is routinely used in guidewire cores to provide elastic tip navigation power in delivery of Co-Ni-Cr alloy self-expanding braids with strengths exceeding 2 GPa. In absorbable wire materials, new strength levels with useful degradation profiles are possible via alloy, composite, and processing strategies. This paper highlights findings from work on FeMn with N and C additions as well as via composites of FeMn with molybdenum to prospect high strength solutions for eventual downsized device service, such as in neurovascular flow diverters.

Resorbable polymer–metal composites hold promise for bone regeneration, combining the bioactivity of magnesium (Mg) with the biocompatibility of polylactic acid (PLA). However, conventional fabrication methods often rely on toxic solvents and lack the design flexibility required for clinical translation. In this study, we present a novel, solvent-free manufacturing approach that integrates Laser Powder Bed Fusion (LPBF) of AZ91 magnesium alloy with compression moulding of PLA. By tuning processing parameters, hybrid structures with varied metal surface morphologies were produced and evaluated. A two-month in vitro degradation study demonstrated that surface morphology critically influences interfacial bonding and structural integrity. Optimized combinations maintained performance over time, underscoring the method’s potential for engineering resorbable implants for bone regeneration.

Biodegradable iron alloys with manganese and copper can act as temporary orthopaedic implants, gradually degrading in the body and eliminating the need for surgical removal. Manganese promotes tissue regeneration by, among other things, stimulating angiogenesis and reducing oxidative stress, as well as influencing macrophage polarisation towards the M2 phenotype. Copper, on the other hand, exhibits anti-inflammatory and anticoagulant effects, promotes collagen synthesis and blood vessel regeneration. In this study, four materials were tested: pure iron (Fe), Fe35Mn alloys, Fe1Cu and Fe35Mn1Cu alloys (designations: Fe, FeMn, FeCu, FeMnCu), which were fabricated by the repeated template method using polyurethane foam. The foams were immersed in a suspension of metal powders with a 5% polyvinyl alcohol solution (1:2 by weight), dried at 95°C for 35 minutes and then sintered in a tube furnace. The resulting samples were analysed for morphology (SEM), chemical composition (EDS), crystalline phases (XRD) and corrosion by potentiodynamic polarisation in HBSS at 37 ± 2°C. The use of foam produced materials with a porous structure that reproduced the template well. However, significant differences were observed between the samples. In the FeCu alloy, the smoothest and thinnest pore walls were obtained. In FeMn and especially FeMnCu, the structure was less homogeneous, and in the case of FeMn, a significant excess of manganese was detected relative to the target content of 35 wt.%, indicating local accumulations of the element and an uneven distribution. This may affect the control of the degradation process and the mechanical properties of the material. The results indicate that the use of the PU template allows regular porous structures to be obtained, but further optimisation of the composition is needed, especially with regard to the content and uniformity of manganese distribution in the alloys.