Human adipose-derived mesenchymal stem cells (hADSCs) have significant therapeutic potential for neurological disorders, but their specific differentiation remains a challenge. In this study, MgCuCa alloys and pure Mg, prepared by melt-spinning, were designed to investigate the effects of their extract liquids on the differentiation of hADSCs. The results indicated that certain concentrations of Mg and MgCuCa extracts, such as 7.73 mM Mg and 5.65 mM MgCuCa, did not exhibit significant cytotoxicity towards hADSCs. Rather, they inhibited the in vitro differentiation of hADSCs into osteoblasts, chondrocytes, and adipocytes. Importantly, these extracts upregulated the expression of neuronal marker genes, including NES, GAP43, and MAP2, suggesting a potential induction of hADSCs towards a neural lineage. RNA sequencing analysis revealed that the differentially expressed genes were predominantly enriched in signaling pathways related to stem cell differentiation, such as Notch, Wnt, TGF-β, PI3K-AKT, and MAPK. Gene set enrichment analysis (GSEA) further suggested the inhibition of these pathways. Additionally, the CuCa components of MgCuCa promoted the expression of SOX9, which may enhance the chondrogenic differentiation of hADSCs. In conclusion, Mg and MgCuCa extracts regulate the fate of hADSCs by inhibiting non-neural differentiation and promoting neural-like differentiation through modulation of key signaling pathways. This study offers new insights into the use of metal-ion-based materials for neural regeneration. Future research should focus on optimizing ion composition, concentration, and pH, as well as considering the type and source of mesenchymal stem cells, to enhance the effectiveness and specificity of hADSC-based therapies for central nervous system diseases.

To clarify the densification behavior, deformation response and strengthening mechanisms of selective laser melted (SLM) Mg-RE alloys, this study systematically investigates a representative WE43 alloy via advanced material characterization techniques. A suitable laser output mode fell into the transition mode, allowing for the fabrication of nearly full-density samples (porosity = 0.85 ± 0.021%) with favorable mechanical properties (yield strength=351 MPa, ultimate tensile strength = 417 MPa, the elongation at break = 6.5% and microhardness = 137.9 ± 6.15 HV_0.1) using optimal processing parameters (P = 80 W, v = 250 mm/s and d = 50 µm). Viscoplastic self-consistent analysis and transmission electron microscopy observations reveal that the plastic deformation response of the SLM Mg-RE alloys is primarily driven by basal <a> and prismatic <a> slips. Starting from a random texture before deformation (maximum multiple of ultimate density, Max. MUD = 3.95), plastic stretching led the grains to align with the Z-axis, finally resulting in a {0001}<1010> texture orientation after fracture (Max. MUD = 8.755). Main phases of the SLM state are mainly composed of α-Mg, Mg₂₄Y₅ and β’-Mg₄₁Nd₅, with an average grain size of only 4.27 µm (about a quarter of that in the extruded state), resulting in a favorable strength-toughness ratio. Except for the nano-β’ phase and semi-coherent Mg₂₄Y₅ phase (mismatch = 16.12%) around the grain boundaries, a small amount of nano-ZrO₂ and Y₂O₃ particles also play a role in dispersion strengthening. The high mechanical properties of the SLM state are chiefly attributed to precipitation hardening (44.41%), solid solution strengthening (34.06%) and grain boundary strengthening (21.53%), with precipitation hardening being predominantly driven by dislocation strengthening (67.77%). High-performance SLM Mg-RE alloy components were manufactured and showcased at TCT Asia 2024, receiving favorable attention. This work underscores the significant application potential of SLM Mg-RE alloys and establishes a strong foundation for advancing their use in the biomedical fields.

In the present research, the NaF assisted plasma electrolytic oxidation (PEO) is designed to fabricate the high-content ZnO nanoparticles doped coating on AZ31B alloy. The microstructure, phase constituents and corrosion behavior of the PEO coatings are investigated systematically. The results reveal that the introduction of NaF promotes the formation of MgF₂ nanophases in the passivation layer on Mg alloy, decreasing the breakdown voltage and discharge voltage. As a result, the continuous arcing caused by high discharge voltage is alleviated. With the increasing of NaF content, the Zn content in the PEO coating is enhanced and the pore size in the coating is decreased correspondingly. Due to the high-content ZnO doping, the PEO coating protected AZ31B alloy demonstrates the better corrosion resistance. Compared with the bare AZ31B alloy, the high-content ZnO doped PEO coated sample shows an increased corrosion potential from -1.465 V to -1.008 V, a decreased corrosion current density from 3.043×10^-5 A·cm^-2 to 3.960×10^-8 A·cm^-2 and an increased charge transfer resistance from 1.213×10² ohm·cm² to 2.598×10⁵ ohm·cm². Besides, the high-content ZnO doped PEO coated sample also has the excellent corrosion resistance in salt solution, exhibiting no obvious corrosion after more than 2000 h neutral salt spraying and 28 days’ immersion testing. The improved corrosion resistance can be ascribed to the relative uniform distribution of ZnO in PEO coating which can transform to Zn(OH)₂ and form a continuous protective layer along the corrosion interface.

In the present work, seven Mg-Zn-Ag alloys with the nominal composition of Mg_96-xZn_xAg₄ (x=17, 20, 23, 26, 29, 32, 35 in at.%) were prepared by induction melting and single-roller melt-spinning. The X-ray diffraction (XRD) analyses indicate the metallic glasses with three composition of Mg₇₃Zn₂₃Ag₄, Mg₇₀Zn₂₆Ag_4, and Mg₆₇Zn₂₉Ag₄ were obtained successfully. The differential scanning calorimetry (DSC) measurement was used to obtain the characteristic temperature of Mg-Zn-Ag metallic glasses for the glass-forming ability analysis. The maximum glass transition temperature (T_rg) was found to be 0.525 with a composition close to Mg₆₇Zn₂₉Ag₄, which results in the best glass-forming ability. Moreover, the immersion test in simulated body fluid (SBF) demonstrate the relative homogeneous corrosion behavior of the Mg-Zn-Ag metallic glasses. The corrosion rate of Mg-Zn-Ag metallic glasses in SBF solution decreases with the increase of Zn content. The sample Mg₆₇Zn₂₉Ag₄ has the lowest corrosion rate of 0.19 mm/yr, which could meet the clinical application requirement well. The in vitro cell experiments show that the Madin-Darby canine kidney (MDCK) cells cultured in sample Mg₆₇Zn₂₉Ag₄ and its extraction medium have higher activity. However, the Mg-Zn-Ag metallic glasses exhibit obvious inhibitory effect on human rhabdomyosarcoma (RD) tumor cells. The present investigations on the glass-forming ability, corrosion behavior, cytocompatibility and tumor inhibition function of the Mg-Zn-Ag based metallic glass could reveal their biomedical application possibility.