Magnesium (Mg) and its alloys have emerged as promising candidates for guided bone/tissue regeneration (GBR/GTR) due to their good mechanical properties, biosafety, and biodegradability. In this study, we present a pioneering application of Mg-Ag alloys featuring tunable corrosion behaviors for GBR/GTR membranes, showcasing their in vitro antibacterial effects, cell migration, and osteogenic differentiation abilities. Mg-Ag alloys with different Ag contents were engineered to facilitate the cell migration of murine fibroblasts (L929) and the osteogenic differentiation of rat bone mesenchymal stem cells (rBMSCs). The Mg-Ag alloy consisted of recrystallized α-Mg grains and fine Mg₄Ag second phases, with an observable refinement in the average grain size to 5.6 µm with increasing Ag content. Among the alloys, Mg-9Ag exhibited optimal mechanical strength and moderate plasticity (tensile yield strength of 205.7 MPa, elongation of 20.3%, and a maximum bending load of 437.2 N). Furthermore, the alloying of Ag accelerated the cathodic reaction of pure Mg, leading to a slightly increased corrosion rate of the Mg-Ag alloys while maintaining acceptable general corrosion. Notably, compared with pure Mg, Mg-Ag alloys had superior antibacterial effects against Porphyromonas gingivalis (P. gingivalis) and Staphylococcus aureus (S. aureus). Taken together, these results provide evidence for the significant clinical potential of Mg-Ag alloys as GBR/GTR membranes.

Magnesium (Mg) alloys with biodegradability and excellent mechanical properties are in high demand for applications in guided bone regeneration (GBR). However, the clinical application of Mg alloys is hindered by infection risks and limited osteogenesis. Herein, a structure-functional integrated Mg-Ca/Mg-Cu bilayer membrane was rolled at 150 ℃ through various single-pass reductions by using online heating rolling. The Mg-Cu layer was specifically engineered to exhibit antibacterial properties tailored for gingival tissue, while the Mg-Ca layer was designed to support bone regeneration within the defect cavity. The bilayer membrane demonstrated a flexural yield strength of 421.0 MPa and a modulus of 58.6 GPa, indicating exceptional deformation resistance. Furthermore, it maintained notable structural stability by retaining 86.4% of its volume after 21 days in Hanks’ solution. In vitro results revealed that the bilayer membrane exhibited favorable biocompatibility and promoted osteogenesis via the synergetic effect of released Mg²⁺ and Ca²⁺ ions. The rapid release of Cu²⁺ ions and the creation of an alkaline environment further improved antibacterial properties, potentially preventing postoperative infections. Additionally, in an in vivo rat calvarial defect model, the membrane demonstrated its capability to stimulate new bone formation. In summary, the Mg-Ca/Mg-Cu bilayer membrane exhibited outstanding mechanical stability, favorable corrosion rates, extraordinary osteogenic and antibacterial activity simultaneously. Consequently, it holds promise as a robust barrier membrane in GBR applications.

Biodegradable magnesium (Mg) alloys are expected to be promising materials for cardiovascular stents (CVS), which can avoid the long-term clinical problems of current CVS, such as in-stent restenosis, late stent thrombosis, etc. Mg alloy stents exhibit superior biocompatibility and tunable biodegradability, compared with conventional permanent metallic stents. However, the poor formability and non-uniform corrosion of Mg alloy stents hinder their clinical application of CVS. This review focuses on the development of Mg alloys for CVS in recent years. According to the results of bibliometric analysis, we analyzed different biodegradable Mg alloy systems. Moreover, the structural design strategies for Mg alloy stents that can reduce the stress concentration, as well as the surface modification methods to control the corrosion behavior and biological performance of Mg alloy stents are also highlighted. At last, this review systematically discussed the potential directions and challenges of biodegradable magnesium stents (BMgS) in cardiovascular fields.