Silk Fiber as the Support and Reductant for the Facile Synthesis of Ag–Fe3O4 Nanocomposites and Its Antibacterial Properties

Abstract

We report a facile and environmentally friendly approach to prepare Ag–Fe3O4–silk fiber nanocomposites. The Ag–Fe3O4–silk fiber acts as: (i) a biocompatible support for the silver nanoparticles; and (ii) a reducing agent for the silver ions. Neither additional reducing agents nor toxic organic solvents were used during the preparation process. The Ag–Fe3O4–silk fiber nanocomposites can be actuated by a small household magnet and have high antibacterial activities against both Escherichia coli and Staphylococcus aureus. These nanocomposites could be easily recycled without a decrease in their antibacterial activities due to the synergistic effects between the Ag NPs and Fe3O4 NPs with large amounts of active sites.

Electroactive Composites with Block Copolymer-Templated Iron Oxide Nanoparticles for Magnetic Hyperthermia Application

“…The chemical structure of the synthesized iron oxide was determined by XRD measurement (Figure 2). The diffraction peaks (2θ) of 30.35°, 35.95°, 43.45°, 53.70°, 57.25°, and 62.88° are consistent with X-ray diffraction from the (220), (311), (400), (422), (511), and (440) planes of face-centered cubic Fe 3 O 4 (JCPDS 87-2334), indicating the synthesized iron oxide nanoparticles are magnetic Fe 3 O 4 [32]. The magnetic properties of the synthesized 12 nm Fe 3 O 4 nanoparticles were studied by SQUID (superconducting quantum interference device) at 300 K. The results (shown in Figure 3) revealed that there was no magnetization hysteresis observed as the applied magnetic field varied, indicating the magnetic particles are in a superparamagnetic state [33].…”

Biological Activity and Nanostructuration of Fe3O4-Ag/High Density Polyethylene Nanocomposites

“…A time-dependent antibacterial effect in 0.1 wt. % of Ag/Fe 3 O 4 was also observed which indicated that the use of specific rotating magnetic fields to manipulate Ag/Fe 3 O 4 magnetic NPs can significantly improve the antibacterial efficacy against E Coli and that the highest antibacterial effect can be achieved to 99.4% [14]. The antibacterial silk from Fe 3 O 4 -Ag with high antibacterial activities against both Escherichia coli and Staphylococcus aureus been also synthesized [15].…”

“…The highest antibacterial effect of 99.4% was achieved at 5.4 wt. % of NPs and the driving frequency of 100 rpm [14]. A time-dependent antibacterial effect in 0.1 wt.…”

Gold, Silver, and Iron Oxide Nanoparticle Incorporation into Silk Hydrogels for Biomedical Applications: Elaboration, Structure, and Properties

“…The latter is composed of a heavy (H-chain, ∼390 kDa) and a light (L-chain, ∼26 kDa) chain, which are covalently bound by a disulfide bond between two cysteines. , The H-chain contains 12 repetitive regions that enable the formation of antiparallel β-sheet structures. , These crystalline regions are responsible for the mechanical properties and degradation rates of silk materials. SF is a versatile material that has been successfully shaped into various scaffolds, including sponges, , electrospun mats, ,− microspheres, , hydrogels, ,− aerogels, − and three-dimensional (3D) printed structures. − Interestingly, these scaffolds are now being applied to develop silk-based bionanocomposites by providing new inputs to the existing SF materials through functionalization. ,− For example, biophotonic devices have been developed by incorporating gold or zinc oxide NPs into silk materials. , Bionanocomposites are achieved through the mixture of SF and nanosized objects, typically nanoparticles (NPs). The incorporation of NPs, in a small amount, within the SF material offers, indeed, new properties that are unattainable by “classical” composites of the same bulk materials.…”