In vivo corrosion behaviour of magnesium alloy in association with surrounding tissue response in rats

Abstract

Biodegradable magnesium (Mg) alloys are the most promising candidates for osteosynthesis devices. However, their in vivo corrosion behaviour has not been fully elucidated. The aim of this study was to clarify the influence of the physiological environment surrounding Mg alloys on their corrosion behaviour. A Mg-1.0Al alloy with a fine-grained structure was formed into plates using titanium (Ti) as a control. These plates were implanted into the subperiosteum in the head, subcutaneous tissue of the back, and in the muscle of the femur of rats for 1, 2 and 4 weeks. The volumes of the remaining Mg alloy and of the insoluble salt deposition and gas cavities around the Mg alloy were determined by microtomography, and the volume losses were calculated. Then, the tissue response around the plates in each implantation site was examined histopathologically, and its relation to the respective volume loss was analyzed. These analyses determined that the Mg alloy was corroded fastest in the head, at an intermediate level in the back, and slowest in the femur. The insoluble salt deposition at the Mg alloy surface had no influence on the volume loss. Gas cavities formed around the Mg alloy at all implantation sites and decreased after 4 weeks. Histopathological examination revealed that the Mg alloy exhibited good biocompatibility, as was seen with Ti. In addition, vascularized fibrous capsules formed around the plates and became mature with time. Notably, the volume loss in the different anatomical locations correlated with capsule thickness. Together, our results suggest that, to facilitate the successful clinical application of Mg alloys, it will be necessary to further comprehend their interactions with specific in vivo environments.

<i>In vitro</i> and <i>in vivo</i> analysis of the biodegradable behavior of a magnesium alloy for biomedical applications

“…Miura et al 27) examined other Mg alloy showing relatively slow corrosion in same way. Mg alloy used in this study showed considerably faster corrosion and more insoluble salt formation than Mg alloy in previous report 27) . However, our results shared its corrosion characteristics in different implanted site.…”

In vivo study of self‐assembled alkylsilane coated degradable magnesium devices

“…48 Miura et al also noticed little infiltration of inflammatory cells around the Mg-Al binary alloy implanted in the rat tissue. 62 Our H&E study provides an overview of the cells and tissues surrounding the implants. The degrading implants can cause myofiber degeneration that can be detected by H&E staining.…”

In vivo analysis of covering materials composed of biodegradable polymers enriched with flax fibers

“…In contrast, the thickness of capsule around PCL flax composites remained unchanged (PCL-wt) or were significantly reduced (PCL-transgen) compared to pure PCL. It is well known, that encapsulation around implants generally occurs as a result of wound healing and foreign body reaction [39, 45]. As described by Miura et al the capsule can be divided into four grades and the histopathological scores significantly decrease with time independently of the implantation site [39].…”

“…It is well known, that encapsulation around implants generally occurs as a result of wound healing and foreign body reaction [39, 45]. As described by Miura et al the capsule can be divided into four grades and the histopathological scores significantly decrease with time independently of the implantation site [39]. A correlation between vascularization and capsule formation was controversially discussed in the literature.…”

“…for the assessment of the encapsulation of test materials in surrounding soft tissue. The evaluation of the granulo-fibrous connective tissue capsule around the composites and division in grades was done as described by Miura et al [39]. …”