Semi-quantitative elemental imaging of corrosion products from bioabsorbable Mg vascular implants in vivo
He et al.
Bioactive Materials, 2025
DOI: 10.1016/j.bioactmat.2024.07.023
최근 발표된 Bioactive Materials, 의 연구원들이 이끄는 Michigan Technical University 그리고 Michigan State University, 를 활용하여 icpTOF S2 coupled to a Bioimage 266 nm laser ablation system from Elemental Scientific Lasers to map the distribution of corrosion products from a bioabsorbable magnesium alloy implant in vascular tissue. This high-resolution technique provides qualitative and semi-quantitative insights into the local concentrations of metal ions and their spatial changes, potentially influenced by macrophages.
Bioabsorbable materials, particularly metals like magnesium, have gained attention as alternatives to permanent implants in vascular and orthopedic devices. While early bioabsorbable materials were polymer-based, such as PEG and PLLA, their mechanical limitations restricted their use in complex applications. Magnesium alloys, especially those containing rare earth elements (REEs), offer improved strength and ductility, making them suitable for devices like vascular stents. Magnesium’s bioabsorption over time aids tissue regeneration and reduces long-term complications such as late stent thrombosis. However, concerns about the biocompatibility of REEs have been raised due to their cytotoxic effects and ability to trigger inflammatory gene expression. Recent studies have explored REE distribution in tissues, but much remains unknown about their migration in soft tissues like arteries.
This recent study used laser ablation inductively coupled plasma time-of-flight mass spectrometry (LA-ICP-TOFMS) to analyze the elemental distribution in soft tissue surrounding a bioabsorbable magnesium vascular implant to better understand their corrosion products. It shows that the corrosion byproducts of the REE-containing magnesium implant are complex, with REE oxides and secondary phases present. The distribution of these corrosion products, indicated by the 89Y/143Nd ratio, varies depending on location and distance from the implant, with 89Y diffusing more readily through vascular tissue than 143Nd. Changes in endogenous iron levels also correspond to shifts in the 89Y/143Nd ratio, potentially influenced by macrophages. In the tissue near the implant (neointima), magnesium concentrations were approximated at 2752 ppm, with the highest levels located at the interface. In adventitial tissue farther from the implant, magnesium concentrations ranged between 828 and 1336 ppm. Yttrium and neodymium concentrations in the neointima were estimated at 64 ppm and 73 ppm, respectively.
These findings demonstrate how our cutting-edge icpTOF imaging technology enables in-situ qualitative and semi-quantitative analysis of elemental distribution of corrosion products in soft tissue surrounding bioabsorbable magnesium vascular implants. This research is a crucial step toward understanding these innovative materials and their properties, helping to ensure their safety.
