Mg(OH)₂ nanoparticles enhance the antibacterial activities of macrophages by activating the reactive oxygen species

Abstract

Infection often causes disastrous consequences in all fields of clinical medicine, especially orthopedics. Hence, critical efforts are being made to engineer novel nanomaterials for the treatment of orthopedic infections due to the high biocompatibility and antibacterial properties they possess. The purpose of this study was to investigate the antibacterial effects of magnesium hydroxide (Mg(OH)2) nanoparticles (NPs) in vitro and determine their possible mechanisms of action. In this study, Escherichia coli was selected as the pathogenic bacteria and it was found that Mg(OH)2 NPs significantly inhibited the growth of E. coli by promoting nucleic acid leakage, inhibiting protein synthesis, and suppressing the metabolic activity. The minimum inhibitory concentration for these bacteria was determined to be 4.4 μg/ml. In vitro flow cytometry and immunofluorescence tests indicated that Mg(OH)2 NPs induced the macrophages to generate reactive oxygen species to kill the bacteria. To understand the mechanisms involved in this process, western blotting was performed and it was found that Mg(OH)2 NPs activated the phosphatidylinositol‐3‐kinase/serine–threonine kinase (PI3K/Akt) signaling pathway of macrophages to enhance their phagocytosis with no obvious cytotoxicity. Thus, Mg(OH)2 NPs are a suitable choice to develop promising agents or coating materials for the treatment of clinically widespread infections in view of their safety, biocompatibility, and powerful antibacterial properties.

Magnesium‐Encapsulated Injectable Hydrogel and 3D‐Engineered Polycaprolactone Conduit Facilitate Peripheral Nerve Regeneration

“…[39] It has also been implicated in pathophysiological processes induced by Mg-based biomaterials. [40] Our results validated that the PI3K/Akt signaling pathway plays a role in Mg-induced neurite outgrowth, as axonal growth density and length were significantly inhibited by the PI3K/Akt inhibitor LY294002. In addition to assessing transcriptional regulation in nerve regeneration, we evaluated the expression levels of axon guidance molecules and neurotrophic factors secreted nerve regeneration.…”

On Antimicrobial Polymers: Development, Mechanism of Action, International Testing Procedures, and Applications

“…The ionic radius of Mg ++ is 72 pm [ 137 ]. The mode of action involves activating ROS [ 141 ]. They are generally considered safe, although high concentrations can cause gastrointestinal complications.…”

Gold Nanoclusters Exert Bactericidal Activity and Enhance Phagocytosis of Macrophage Mediated Killing of Fusobacterium nucleatum

“…Bernut et al recently found reduced ROS production by macrophages could inhibit their ability to control bacteria and subsequently lead to their death (Bernut et al, 2019). In contrast, Mg (OH) 2 nanoparticles have been implicated in enhanced antibacterial activities of macrophages by activating the reactive oxygen species (Zhu et al, 2021). Therefore, a strategy to enhance ROS generation of macrophages and promote immunoregulatory response is a potential therapy to combat bacterial pathogens and control infections.…”