Synergistic\nDual Antibacterial Activity of Magnetite\nHydrogels Doped with Silver

In this work, we utilized poly-<i>N</i>-isopropylacrylamide\n(NIPAM), magnetic nanoparticles (MNPs), and silver nitrate to prepare\nmagnetic hydrogel microparticles doped with silver, which exhibited\na dual antimicrobial effect. The antibacterial effect of these composites\nwas mediated by the antimicrobial activity of silver and the magnetic\nhyperthermic induction, which we believe increased biofilm disruption\nand silver release into the surrounding bacterial biofilms. The prepared\nparticles were characterized by using several analytical techniques.\nThe particles exhibited a porous morphology impregnated evenly with\nsilver nanoparticles, as observed by scanning electron microscopy\n(SEM). Furthermore, we examined the antibacterial activity of our\nmicroparticles against Escherichia coli by determining the minimum inhibitory concentration (MIC) and minimum\nbactericidal concentration (MBC). Our findings revealed that the composites\ndemonstrated significant antibacterial activity of up to 81% under\nmagnetic hyperthermia as compared to 45% when samples were heated\nto the same temperature in a water bath at constant silver concentration.\nThis demonstrates the distinctive inhibitory features of MNPs in enhancing\nbacterial killing when a magnetic field is applied. The findings of\nthis study lay the groundwork for further exploration of microparticle-based\nantimicrobial therapies, which can contribute to the development of\nmore advanced wound healing devices and better sterilization methods\nfor medical devices.