Insights into heat treatments of biodegradable Mg-Y-Nd-Zr alloys in clinical settings: Unveiling roles of β' and β nanophases and latent in vivo hydrogen evolution.

Heat treatment serves as a viable strategy to effectively mitigate the intense corrosion of biodegradable WE43 alloys. However, limited comprehension of the passivation mechanisms underlying heat treatment and the dilemma to quantitatively examine the evolution of hydrogen gas in vivo introduce uncertainties in designing heat treatments for developing clinically applicable WE43. This work aims to advance this knowledge by applying cutting-edge atom probe tomography to provide atomic-scale insights into the passivation roles of rare earth (RE)-rich β (Mg(Y, Nd)) and β' (MgNdY) nanophases induced by T6 heat treatment at 250 °C, and employing machine learning-based image analysis techniques to quantitatively unveil WE43's in vivo gas evolution during a 12-week implantation.

Zinc-based subcuticular absorbable staples: An in vivo and in vitro study.

A zinc-nutrient element alloy (Zn-1.0Cu-0.5Ca) was developed into subcuticular absorbable staples (SAS) as a robust alternative to the commercially available poly(l-lactide-co-glycolide) (PLGA) SAS for the first time.

Exploring the Influence of Biologically Relevant Ions on the Corrosion Behavior of Biodegradable Zinc in Physiological Fluids.

This work presents a study on the influence of biologically relevant ions on the corrosion of zinc (Zn) in physiological fluids. Electrochemical techniques were used to investigate the degradation of pure Zn exposed to different physiological electrolytes containing chlorides, carbonates, sulfates, and phosphates. The corrosion behavior of Zn in the solutions over a 7-day period was also assessed.

Fabrication and Properties of Biodegradable Akermanite-Reinforced Fe35Mn Alloys for Temporary Orthopedic Implant Applications.

As a representative of the biodegradable iron (Fe)-manganese (Mn) alloys, Fe35Mn has been investigated as a promising biodegradable metal biomaterial for orthopedic applications. However, its slow degradation rate, though better than pure Fe, and poor bioactivity are concerns that retard its clinical applications. Akermanite (CaMgSiO, Ake) is a silicate-based bioceramic, showing desirable degradability and bioactivity for bone repair.

Evolution of degradation mechanism and fixation strength of biodegradable Zn-Cu wire as sternum closure suture: An in vitro study.

This work reports the first in vitro study on the in-situ biodegradation behaviour and the evolution of fixation strength of Zn-Cu alloy wires in a simulated sternum closure environment. Zn-Cu wires were used to reapproximate the partial bisected sternum models, and their fixation effect was compared with traditional surgical grade 316 L stainless steel (SS) wires in terms of fixation rigidity, critical load, first/ultimate failure characteristics. The metal sutures were then immersed in Hank's balanced salt solution for 12 weeks immersion period, and their corrosion behaviours assessed.

Expedient secondary functions of flexible piezoelectrics for biomedical energy harvesting.

Flexible piezoelectrics realise the conversion between mechanical movements and electrical power by conformally attaching onto curvilinear surfaces, which are promising for energy harvesting of biomedical devices due to their sustainable body movements and/or deformations. Developing secondary functions of flexible piezoelectric energy harvesters is becoming increasingly significant in recent years via aiming at issues that cannot be addressed or mitigated by merely increasing piezoelectric efficiencies. These issues include loose interfacial contact and pucker generation by stretching, power shortage or instability induced by inadequate mechanical energy, and premature function degeneration or failure caused by fatigue fracture after cyclic deformations.

An overview and critical assessment of the mechanisms of microstructural refinement during ultrasonic solidification of metals.

A refined, equiaxed grain structure and the formation of finer primary intermetallic phases are some of the notable benefits of ultrasonic processing of liquid/solidifying melts. Ultrasonic treatment (UST) has been widely explored in Al and Mg-based alloys due to its operational versatility and scalability. During UST, the refinement of grain and primary intermetallic phases occurs via cavitation-induced fragmentation mechanisms.

Design, mechanical and degradation requirements of biodegradable metal mesh for pelvic floor reconstruction.

Pelvic organ prolapse is the herniation of surrounding tissue and organs into the vagina and/or rectum and is a result of the weakening of pelvic floor muscles, connective tissue, and fascia. It is widely accepted that 50% of women will develop prolapse, with the prevalence increasing with age, and up to 10-20% of those seek evaluation for their condition. Suture repairs of pelvic floor defects are associated with a high failure rate, and permanent meshes were introduced to reduce the recurrence rate.

In vivo performance of a rare earth free Mg-Zn-Ca alloy manufactured using twin roll casting for potential applications in the cranial and maxillofacial fixation devices.

A magnesium alloy containing essential, non-toxic, biodegradable elements such as Ca and Zn has been fabricated using a novel twin-roll casting process (TRC). Microstructure, mechanical properties, in vivo corrosion and biocompatibility have been assessed and compared to the properties of the rare earth (RE) element containing WE43 alloy. TRC Mg-0.

Zinc-nutrient element based alloys for absorbable wound closure devices fabrication: Current status, challenges, and future prospects.

The need for the development of load-bearing, absorbable wound closure devices is driving the research for novel materials that possess both good biodegradability and superior mechanical characteristics. Biodegradable metals (BMs), namely: magnesium (Mg), zinc (Zn) and iron (Fe), which are currently being investigated for absorbable vascular stent and orthopaedic implant applications, are slowly gaining research interest for the fabrication of wound closure devices. The current review presents an overview of the traditional and novel BM-based intracutaneous and transcutaneous wound closure devices, and identifies Zn as a promising substitute for the traditional materials used in the fabrication of absorbable load-bearing sutures, internal staples, and subcuticular staples.

Biodegradable shape memory alloys: Progress and prospects.

Shape memory alloys (SMAs) have a wide range of potential novel medical applications due to their superelastic properties and ability to restore and retain a 'memorised' shape. However, most SMAs are permanent and do not degrade in the body when used in implantable devices. The use of non-degrading metals may lead to the requirement for secondary removal surgery and this in turn may introduce both short and long-term health risks, or additional waste disposal requirements.

The influence of Ca and Cu additions on the microstructure, mechanical and degradation properties of Zn-Ca-Cu alloys for absorbable wound closure device applications.

Novel ternary Zn-Ca-Cu alloys were studied for the development of absorbable wound closure device material due to Ca and Cu's therapeutic values to wound healing. The influence of Ca and Cu on the microstructure, mechanical and degradation properties of Zn were investigated in the as-cast state to establish the fundamental understanding on the Zn-Ca-Cu alloy system. The microstructure of Zn-0.

In Vivo Evaluation of Bioabsorbable Fe-35Mn-1Ag: First Reports on In Vivo Hydrogen Gas Evolution in Fe-Based Implants.

This work investigates the influence of Ag (1 wt%) on the mechanical properties, in vitro and in vivo corrosion, and biocompatibility of Fe-35Mn. The microstructure of Fe-35Mn-1Ag possesses a uniform dispersion of discrete silver particles. Slight improvements in compressive properties are attributed to enhanced density and low porosity volume.

Additively manufactured iron-manganese for biodegradable porous load-bearing bone scaffold applications.

Selective laser melting (SLM) can produce complex hierarchical architectures paving the way for highly customisable biodegradable load-bearing bone scaffolds. For the first time, an in-depth analysis on the performance of SLM-manufactured iron-manganese bone scaffolds suitable for load-bearing applications is presented. Microstructural, mechanical, corrosion and biological characterisations were performed on SLM-manufactured iron-manganese scaffolds.

Comparison of the Microstructure and Biocorrosion Properties of Additively Manufactured and Conventionally Fabricated near β Ti-25Nb-3Zr-3Mo-2Sn Alloy.

The microstructure and biodegradability of a near β Ti-25Nb-3Zr-3Mo-2Sn alloy produced by laser engineered net shaping have been compared to those of alloys produced via casting and cold rolling in order to identify the key effects of processing pathways on the development of microstructure and biocorrosion properties. Results confirm the significant influence of processing technique on microstructure and concomitant biocompatibility of the alloy. Tests using mesenchymal stem cells confirm the ability of the additively manufactured alloy to support cell adhesion and spreading.

- Observation of the Continuous Phase Transition in Determining the High Thermoelectric Performance of Polycrystalline SnSe.

We report a comprehensive - phase-change study on polycrystalline SnSe via high-temperature X-ray diffraction and - high-voltage transmission electron microscopy from room temperature to 843 K. The results clearly demonstrate a continuous phase transition from to starting from 573 to 843 K, rather than a sudden transition at 800 K. We also find that the thermal-conductivity rise at high temperature after the phase transition, as commonly seen in pristine SnSe, does not occur in SnSe, leading to a high thermoelectric figure of merit.

The Prospects for Biodegradable Zinc in Wound Closure Applications.

Zinc is identified as a promising biodegradable metal along with magnesium and iron. In the last 5 years, considerable progress is made on understanding the mechanical properties, biodegradability, and biocompatibility of zinc and its alloys. A majority of these studies have focused on using zinc for absorbable cardiovascular and orthopedic device applications.

Exploring the Role of Manganese on the Microstructure, Mechanical Properties, Biodegradability, and Biocompatibility of Porous Iron-Based Scaffolds.

In this work, the role that manganese plays in determining the structure and performance of sintered biodegradable porous Fe-Mn alloys is described. Powder metallurgy processing was employed to produce a series of biodegradable porous Fe-Mn ( = 20, 30, and 35 wt %) alloys suitable for bone scaffold applications. Increasing manganese content increased the porosity volume in the sintered alloys and influenced the ensuing properties of the metal.