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

Abstract

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., 40:2901–2907, 2019. © 2018 Society of Plastics Engineers

Antimicrobial activity of amino-modified cellulose nanofibrils decorated with silver nanoparticles

“…The high content of free amino groups, estimated to be around 5.0 mM/g, is a signi cant feature of NH 2 − CNFs. The amino groups are reactive and capable of reducing silver ions to metallic silver, free [23,24], or attached to inorganic [28,29] or organic [25][26][27] supports. So, in the second synthetic step (Scheme 1), Ag NPs were in-situ prepared by the electron transfer reaction from the amino groups and their transformation into imino groups, and thus conjugated to CNFs over the lone electron pairs of the N atoms from amino groups [24,28,29].…”

“…In the next step, the Ag NPs were grown onto NH 2 − CNFs by the in-situ reduction of Ag + ions, taking advantage of the reducing ability of free amino groups, which are present in the amino-functionalized CNFs [27]. Brie y, the mixture having a 1:1 molar ratio between Ag + ions and amino groups (85 mg of AgNO 3 and 2.1 mL of amino-functionalized CNFs in 50 mL of H 2 O) was stirred overnight under re ux at 60°C.…”

“…On one side, amino-functionalized cellulose nano brils (NH 2 − CNFs) display antimicrobial activity due to the electrostatic interaction between positively charged amino groups and negatively charged cell walls that enhanced their contact with microorganisms [20][21][22]. On the other side, the free amino groups are capable of reducing Ag + ions to their metallic form, providing the possibility to prepare free-standing colloidal Ag NPs [23,24] or Ag NPs linked to different types of supports, polymer [25][26][27] and inorganic [28,29], with high antimicrobial activity. Besides the antimicrobial activity of Ag NPs on support, when they are easily accessible to microbial species in the surrounding medium, Ag NPs dispersed within a polymer matrix also have antimicrobial activity.…”

Preparation and characterization of novel glycidyl methacrylate/clay nanocomposites

“…In addition, GMA-co-EGDMA copolymers are often obtained in the form of macroporous beads, with very attractive porosity that can be easily adapted and optimized by adjusting the composition and conditions of the reaction mixture. Also, it offers a large surface area, with a plenty of high reactive epoxy groups in the side of their polymer chains, suitable to do various chemical functionalization for heavy metal ion and textile dyes removal [3,4], protein separation [5] and supports for controlled release of enzymes [6], drugs [7] or antibacterial agents [8].…”