Heat treatment processes play a pivotal role in optimizing the microstructure and mechanical properties of Mg-Li alloys, thereby enhancing their performance and expanding their potential applications in structural and lightweight engineering fields. In this study, the influence of solution and aging treatments on the microstructure, phase transformation, and microhardness of friction-stir-processed (FSPed) LAZ931 Mg-Li alloy was investigated to obtain the optimal solution treatment temperature and time. An optimal solution treatment at 460 °C for 0.5 h under an Ar gas atmosphere facilitated complete α-phase dissolution with subsequent aging at 125 °C, triggering precipitation-mediated hardening. An X-ray diffraction (XRD) analysis identified a new MgLi₂Al phase in the stirring zone (SZ) in addition to the α, β, and AlLi phases. Aging kinetics at 125 °C showed that SZ hardness increased to 110.5 HV after solution treatment, which was 5.3% higher than the base metal (BM). After 3 h of aging, microhardness peaked at 86.5 HV before decreasing due to the decomposition of the metastable MgLi₂Al phase into the stable AlLi phase. The microhardness stabilized at around 78 HV, which was 16.2% higher than that of the original SZ. These experimental results provide a fundamental understanding of property structure for meeting the growing demand for lightweight materials and improving material properties.

Elucidating the interfacial interaction mechanisms between biomolecules and metal surfaces is crucial for designing functionalized biomedical materials. This study employs first-principles calculations based on density functional theory (DFT) to investigate the adsorption behaviors of arginine (Arg), glutamic acid (Glu), aspartic acid (Asp), and valine (Val) on magnesium (Mg) and Mg alloy surfaces. The adsorption behaviors of four kinds of amino acids on Mg and Mg alloy surfaces were analyzed through optimized adsorption configurations, adsorption energies (E_ads), bond lengths, projected densities of states (PDOSs), and differential charge densities. The calculated results of E_ads followed the order of Arg > Glu > Asp > Val, driven by functional group spatial configurations and electron transfer efficiency. Alloying elements facilitated charge redistribution on the Mg and Mg alloy surfaces, enhancing the interaction between amino acids and the alloy surfaces. Notably, the guanidino group of Arg exhibited exceptional adsorption stability and multi-dentate bonding, increasing electron donation to the Mg(0001) surface, achieving the highest E_ads (−1.67 eV). This work provides insights into the structure–activity relationships between amino acids and Mg and Mg alloy surfaces, offering a foundation for designing biomolecule-derived functional coatings and strategies for improving the biocompatibility of Mg and Mg alloy implants.

Extracellular vesicles (EVs), naturally secreted by cells as nanoscale lipid bilayer structures, have become a research hotspot in biomedicine owing to their excellent biocompatibility, low immunogenicity, and inherent ability to cross biological barriers. This review systematically summarizes recent advances in EVs as natural nanomaterials. The biogenesis mechanisms of EVs are outlined, followed by a comparative analysis of the advantages and limitations of mainstream isolation and purification methods, including ultracentrifugation, size-exclusion chromatography, and microfluidic technologies. The core guiding role of the MISEV 2023 guidelines in standardizing EV characterization is highlighted. Engineering strategies to enhance EV therapeutic efficacy—including parental cell modification, post-isolation physicochemical tailoring, and hybrid vesicle construction—are then reviewed, followed by a comparative analysis of mainstream isolation technologies, emphasizing the trade-offs between purity and yield. Distinct from conventional descriptive reviews, this article establishes a strong biomimetic framework to scrutinize engineering strategies, including parental cell genetic modification, post-isolation physicochemical tailoring, and the fabrication of hybrid bio-synthetic vesicles. The design principles governing targeted delivery, drug-loading physics, and in vivo pharmacokinetic stability are critically evaluated through the lens of biomimetic nanotechnology. Furthermore, we identify critical research gaps and technical bottlenecks impeding clinical translation, offering a forward-looking perspective on the evolution of EVs from natural messengers into standardized precision medicine platforms.