Size‐dependent antibacterial properties of Ag nanoparticles supported by amino‐functionalized poly(GMA‐ co ‐EGDMA) polymer

Size-dependent antimicrobial ability of silver nanoparticles (Ag NPs) supported by amino-functionalized poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) (poly(GMA-co-EGDMA)) macroporous copolymer was tested against Gram-negative bacteria Escherichia coli. Inorganic/organic hybrids with distinctly different average sizes of Ag NPs (6.6 and 12.1 nm) were prepared by functionalization of poly(GMA-co-EGDMA) with either 1,8-diaminooctane or ammonia, and consequent reduction of silver ions with amino groups. The transmission electron microscopy (TEM), infrared and UV–Vis reflection spectroscopy, elemental analysis, and inductively coupled plasma atomic emission measurements were used to characterize synthesized hybrid materials. Time- and concentration-dependent antimicrobial performances of prepared samples revealed higher reduction rates of E. coli when hybrid with smaller in size Ag NPs was used. The difference between rates of reduction of E. coli for different size Ag NPs is becoming more pronounced by decrease of the concentration of silver. POLYM. COMPOS., 2018. © 2018 Society of Plastics Engineers. © 2018 Society of Plastics Engineer

Synthesis, characterization, and antimicrobial activity of poly(GMA-co-EGDMA) polymer decorated with silver nanoparticles

Composite consisting of silver nanoparticles coordinated to poly(GMA-co-EGDMA) macroporous copolymer was prepared by attachment of amino group to the poly(GMA-co-EGDMA) in the reaction with ethylene diamine, and consequent reduction of silver ions with amino groups at elevated temperature. The infrared measurements indicated that surface of silver nanoparticles is passivated through the coordination of the lone pair on the N atom of the imine present in the skeleton of the poly(GMA-co-EGDMA) copolymer. The inductively coupled plasma atomic emission, UV-Vis reflection spectroscopy, X-ray diffraction, and transmission electron microscopy measurements revealed the high content (52 wt%) of well-separated silver nanoparticles in the size range of 5-10 nm onto composite. Antimicrobial efficiency of composite was tested against Gram-negative bacteria E. coli, Gram-positive bacteria S. aureus, and fungus C. albicans in wide concentration range of composite. The composite ensured almost maximum reduction of both bacteria, while the fungi reduction reached 96.5 %

Nanomaterial with High Antimicrobial Efficacy-Copper/Polyaniline Nanocomposite

This study explores different mechanisms of antimicrobial action by designing hybrid nanomaterials that provide a new approach in the fight against resistant microbes. Here, we present a cheap copper-polyaniline (Cu-PANI) nanocomposite material with enhanced antimicrobial properties, prepared by simple in situ polymerization method, when polymer and metal nanoparticles are produced simultaneously. The copper nanoparticles (CuNPs) are uniformly dispersed in the polymer and have a narrow size distribution (dav = 6 nm). We found that CuNPs and PANI act synergistically against three strains, Escherichia coli, Staphylococcus aureus, and Candida albicans, and resulting nanocomposite exhibits higher antimicrobial activity than any component acting alone. Before using the colony counting method to quantify its time and concentration antimicrobial activity, different techniques (UV-visible spectroscopy, transmission electron microscopy, scanning electron microscope, field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectrophotometry, and inductively coupled plasma optical emission spectrometry) were used to identify the optical, structural, and chemical aspects of the formed Cu-PANI nanocomposite. The antimicrobial activity of this nanocomposite shows that the microbial growth has been fully inhibited; moreover, some of the tested microbes were killed. Atomic force microscopy revealed dramatic changes in morphology of tested cells due to disruption of their cell wall integrity after incubation with Cu-PANI nanocomposite