Iron Oxide@PEDOT-Based Recyclable Photothermal Nanoparticles with Poly(vinylpyrrolidone) Sulfobetaines for Rapid and Effective Antibacterial Activity

Abstract

Growing microbial resistance that renders antibiotic treatment vulnerable has emerged, attracting a great deal of interest in the need to develop alternative antimicrobial treatments. To contribute to this effort, we report magnetic iron oxide (Fe3O4) nanoparticles (NPs) coated with catechol-conjugated poly(vinylpyrrolidone) sulfobetaines (C-PVPS). This negatively charged Fe3O4@C-PVPS is subsequently encapsulated by poly(3,4-ethylenedioxythiophene) (PEDOT) following a layer-by-layer (LBL) self-assembly method. The obtained Fe3O4@C-PVPS:PEDOT nanoparticles appear to be novel NIR-irradiated photothermal agents that can achieve effective bacterial killing and are reusable after isolation of the used particles using external magnetic fields. The recyclable Fe3O4@C-PVPS:PEDOT NPs exhibit a high efficiency in converting photothermal heat for rapid antibacterial effects against Staphylococcus aureus and Escherichia coli. In this study, antibacterial tests for repeated uses maintained almost 100% antibacterial efficiency during three cycles and provided rapid and effective killing of 99% Gram-positive and -negative bacteria within 5 min of near-infrared (NIR) light exposure. The core-shell nanoparticles (Fe3O4@C-PVPS:PEDOT) exhibit the required stability, and their paramagnetic nature means that they rapidly convert photothermal heat sufficient for use as NIR-irradiated antibacterial photothermal sterilizing agents.

Photothermal conversion upon near-infrared irradiation of fluorescent carbon nanoparticles formed from carbonized polydopamine

“…6 shows the percentage of bacteria killed aer 5 min NIR exposure; and illustrates that killing efficiency increased with sample concentration. 22 However, the FNP-pDA treated agent exhibits more prominent antibacterial efficiency compared with surface-passivated FNPpDA. Aer 5 min of NIR treatment with nanoparticles at a concentration of 0.5 mg mL À1 , almost 80% of bacteria were killed in the FNP-pDA treated group; while in the group treated with surface-passivated FNP-pDA, only 60% were killed under identical experimental conditions.…”

Synthesis and antibacterial activity of surface‐coated catechol‐conjugated polymer with silver nanoparticles on versatile substrate

“…[31] Both these peaks are attributed to Ag 0 species, indicating the presence of zerovalent AgNPs in the prepared nanocomposite. [24,34,35] We used an ellipsometer to measure the surface thicknesses of the substrates coated with C-PgP and C-PgP/AgNPs ( Table 1). The surface thickness of Si, Ti, and Au wafers coated with C-PgP was 41.96, 21.31, and 32.27 Å, respectively; after deposition of AgNPs, the thickness increased to 121.29, 66.41, and 658.92 Å, respectively.…”

NIR‐Mediated Antibacterial Clay Nanocomposites: Exfoliation of Montmorillonite Nanolayers by IR825 Intercalation

“…Moreover, the higher ratio of MMT (C/IR825‐PVPS:MMT = 95:5 and C/IR825‐PVPS:MMT = 90:10) intercalated lower contents of IR825 containing polymer and decrease NIR response which result in low generation of photothermal heat (Figure S3). The photo‐thermal results of C/IR825‐PVPS:MMT = 99:1 have therefore encouraged us to verify the antibacterial activity by using NIR light …”

“…As a result, photothermal eradication can distinguish the treatment area and protect the unwanted damage of non‐irradiated area . Following irradiation, the bacteria were stained using SYTO 9 and PI (live/dead) . The fluorescence microscopic images in Figure a show that both gram positive ( S. aureus ) and gram negative ( E. coli ) bacteria were completely destroyed (red color/ dead cells) after NIR exposure while the cells treated without NIR irradiation remained alive (green color) (Figure S4).…”