Ultrahigh antibacterial response and biochemical activity in Mg-Sn-HA material systems

The effects of metallic tin(Sn) and hydroxyapatite(HA) ceramic particles on metallic magnesium's mechanical properties and antibacterial (S.aureus) response along with bioactivity (toxicity) against D.melanogaster larvae, including the impact on survival, development, sex, longevity, were studied. Three different variations of self-assembled Mg-based materials were synthesized by mechanical alloying and densification of the samples was accomplished by hot press sintering. SEM analysis reveals that the smallest particle morphology was obtained in the Mg-3Sn alloy wherein excessive plastic deformation resulted in a monodisperse particle distribution, enabling uniform distribution of reinforcing elements. The most significant gain in mechanical properties was observed in the Mg-Sn system in which the formation of the Mg2Sn intermetallic results Brinell hardness of 184, corresponding ∼ 500 % increase relative to pure Mg. The intermetallic Mg2Sn phase and its high-volume fraction in the Mg matrix leads hardening by the Orowan mechanism. In all treatment groups, the overall survival rate is ≥ 80 %, which shows that the produced alloys and composites are not neither toxic nor lethal to the model organisms. According to the survival rate and development time data, it was determined that the sex of the organisms shifted in favor of the first group (males) and the second group (females), while the oxidative stress (OSI) increased in organisms in contact with the first group (males). The Mg-HA and Mg-Sn-HA systems exhibit superb antibacterial properties, showing complete inhibition of S.aureus after 24-h incubation period. Overall, such alloys could have a significant impact on a range of clinical and biomedical applications because of their outstanding antibacterial properties as demonstrated in this study.