Synergistic effect of static magnetic field and HA-Fe3O4 magnetic composites on viability of S. aureus and E. coli bacteria.
In addressing the issue of prosthetic infection, this work demonstrated the synergistic effect of the application of static magnetic field (SMF) and ferrimagnetic substrate properties on the bactericidal property in vitro. This aspect was studied using hydroxyapatite (HA)-xFe3 O4 (x=10, 20, and 40 wt.%) substrates, which have different saturation magnetization properties. During bacteria culture experiments, 100 mT SMF was applied to growth medium (with HA-xFe3 O4 substrate) in vitro for 30, 120, and 240 min. A combination of MTT assay, membrane rupture assays, live/dead assay, and fluorescence microscopic analysis showed that the bactericidal effect of SMF increases with the exposure duration as well as increasing Fe3 O4 content in biomaterial substrates. Importantly, the synergistic bactericidal effect was found to be independent of bacterial cell type, as similar qualitative trend is measured with both gram negative Escherichia coli (E. coli) and gram positive Staphylococcus aureus (S. aureus) strains. The reduction in E. coli viability was 83% higher on HA-40 Wt % Fe3 O4 composite after 4 h exposure to SMF as compared to nonexposed control. Interestingly, any statistically significant difference in ROS was not observed in bacterial growth medium after magnetic field exposure, indicating the absence of ROS enhancement due to magnetic field. Overall, this study illustrates significant role being played by magnetic substrate compositions towards bactericidal property than by magnetic field exposure alone.
['Bajpai|Indu|I|', 'Balani|Kantesh|K|', 'Basu|Bikramjit|B|']
D000900:Anti-Bacterial Agents D001422:Bacterial Adhesion D001672:Biocompatible Materials D002462:Cell Membrane D002463:Cell Membrane Permeability D004396:Coloring Agents D017886:Durapatite D004926:Escherichia coli D005290:Ferric Compounds D060526:Magnetic Fields D008855:Microscopy, Electron, Scanning D008856:Microscopy, Fluorescence D017382:Reactive Oxygen Species D013211:Staphylococcus aureus D013778:Tetrazolium Salts D013844:Thiazoles
static magnetic field bactericidal effect magnetic biocomposites