Effects of intramuscular administration of Mg-Zn alloys on tissue and blood parameters in rats

Magnesium-zinc (Mg-Zn) alloys are widely investigated as potential biodegradable biomaterials, but their systemic safety and tissue-level effects remain incompletely understood. This study aimed to evaluate the biochemical and histopathological responses to intramuscular implantation of Mg-Zn alloys in rats. Thirty-two male Wistar albino rats were randomly assigned to four groups: Control, Mg, MgZn1, and MgZn3, and sacrificed at the 4th and 7th weeks. Blood samples were collected for lipid profile, liver and kidney function tests, and protein analysis. Histopathological examinations of muscle, brain, kidney, liver, and spleen tissues were performed using hematoxylin and eosin (H&E) staining. Biochemical analysis revealed no statistically significant differences among groups (p ≥ 0.05), although the MgZn3 group showed mild elevations in kidney function markers. Histological evaluation demonstrated preserved cortical and hepatic architecture, mild edema and vascular congestion in muscle tissue, focal tubulitis and interstitial lymphocyte infiltration in kidneys, and increased numbers of debris-laden macrophages in spleen sections of MgZn3 animals. No severe or life-threatening alterations were detected. In conclusion, Mg-Zn alloys exhibited favorable short-term biocompatibility with only limited systemic and histological changes, while higher zinc content (MgZn3) was associated with mild renal and splenic responses. These findings highlight the need for further long-term studies using complementary staining methods to confirm safety for biomedical applications.