Synthesis and characterization of magnetic Ag-Fe₃O₄@polymer hybrid nanocomposite systems with promising antibacterial...

Bacterial infections caused by different strains of bacteria still one of the most important disorders affecting humans worldwide. Polymers nanocomposite systems could be considered as an alternative to conventional antibiotics to eradicate bacterial infections.

In an attempt to enhance the antibacterial performance of silver and iron oxide nanoparticles, decrease their aggregation and toxicity, a polymeric hybrid nanocomposite system combining both nanoparticles is produced.

Magnetic Ag-Fe₃O₄@polymer hybrid nanocomposites prepared using different polymers, namely polyethylene glycol 4000, ethyl cellulose, and chitosan were synthesized via wet impregnation and ball-milling techniques. The produced nanocomposites were tested for their physical properties and antibacterial activities.

XRD, FT-IR, VSM, and TEM results confirmed the successful preparation of hybrid nanocomposites. Hybrid nanocomposites have average crystallite sizes in the following order Ag-Fe₃O₄@CS (8.9 nm) < Ag-Fe₃O₄@EC (9.0 nm) < Ag-Fe₃O₄@PEG4000 (9.4 nm) and active surface area of this trend Ag-Fe₃O₄@CS (130.4 m²g^-1) > Ag-Fe₃O₄@EC (128.9 m²g^-1) > Ag-Fe₃O₄@PEG4000 (123.4 m²g^-1). In addition, they have a saturation magnetization in this order: Ag-Fe₃O₄@PEG4000 (44.82 emu/g) > Ag-Fe₃O₄@EC (40.14 emu/g) > Ag-Fe₃O₄@CS (22.90 emu/g). Hybrid nanocomposites have a pronounced antibacterial action against Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus intermedius compared to iron oxide nanoparticles and positive antibacterial drug. In addition, both Ag-Fe₃O₄@EC and Ag-Fe₃O₄@CS have a lower MIC values compared to Ag-Fe₃O₄@PEG and positive control.

Magnetic Ag-Fe₃O₄ hybrid nanocomposites could be promising antibacterial nanomaterials and could pave the way for the development of new materials with even more unique properties and applications.