Search Results (2)

Mg alloys hold promise for biodegradable gastrointestinal implants, but most evaluations rely on simplified media like Hank’s solution, which lacks organic components and fails to replicate the acidic-to-alkaline transition of intestinal fluid, risking underestimation of biodegradation rates and clinical relevance. This work investigated a trace-Cu-modified Mg alloy (Mg-0.05Cu) in simulated intestinal fluid (SIF) versus Hank’s solution. Microstructural analysis confirmed Mg₂Cu intermetallic phases as Cu reservoirs. Electrochemical and immersion tests revealed significantly accelerated biodegradation in SIF, due to its disruption of protective layer formation, sustaining loose biodegradation products. The biodegradation rate of the trace-Cu-modified Mg alloy in SIF was consistent with reported values for Mg alloys in similar media, as was that in Hank’s solution. Remarkably, Mg-0.05Cu exhibited potent antibacterial activity against E. coli, achieving 99.3% eradication within 12 h and 100% elimination by 24–48 h, alongside excellent cytocompatibility with L929 cells (>95% viability). This efficacy arose from the synergistic Cu²⁺ release and high-pH microenvironment. These findings demonstrate that trace Cu alloying in high-purity Mg balances rapid antibacterial action with controlled biodegradation in a physiologically relevant SIF. This positions Mg-0.05Cu as a highly promising candidate for practical applications, such as biodegradable intestinal stents, anti-adhesion barriers, anastomosis rings, and anti-obesity devices, where rapid infection control and predictable degradation are critical for clinical success. This work underscores the importance of using biomimetic media for evaluating gastrointestinal implants and establishes Mg-0.05Cu as a promising strategy for developing infection-resistant biodegradable devices. Full article

Commercial AlSi7Mg alloy represents the usual choice for complex geometry casting production. The market imperative to improve mechanical properties imposed the design of new chemical composition of AlSi7MgCu alloy with high content of Cu (up to 1.435 wt.%). This represents a challenge in order to achieve advanced properties. The interaction of a number of alloying (Si, Mg, Cu) and trace elements (Fe, Mn) influenced a wide range of complex reactions occurring and therefore leading to intermetallic phase precipitation. The characterization of novel chemical composition interaction and its solidification sequence was achieved by modelling an equilibrium phase diagram, simultaneously performing both thermal analysis and metallographic investigations. Copper influence was indicated in the whole solidification process starting with infiltration in modified Chinese script phase Al₁₅(Fe,Mn,Cu)₃Si₂, beside common intermetallic Al₅FeSi. Copper addition encourages formation of compact complex intermetallic phases Al₅Cu₂Mg₈Si₆ and Al₈(Fe,Mn,Cu)Mg₃Si₆. Solidification ended with secondary eutectic α_Al + Al₂Cu + β_Si. Microstructure investigation allows volume reconstruction of the microstructure and distribution of particular phases. Chemical compositions enriched in copper content and developed microstructural constituent through solidification sequence of AlSi7MgCu alloy contribute to a significant increase in mechanical properties already in an as-cast state. Full article