Cotton Fabric Modified with a PAMAM Dendrimer with Encapsulated Copper Nanoparticles: Antimicrobial Activity

Abstract

A new methodology for modifying textile materials with dendrimers containing nanoparticles was developed. This involved a combination of eosin Y and N-methyldiethanolamine (MDEA) for reducing the copper ions in the dendrimer complex by enabling a photochemical reaction under visible light and ambient conditions. The conversion of copper ions into nanoparticles was monitored using scanning electron microscopy (SEM) and by performing colorimetric, fluorescence, and electron paramagnetic resonance (EPR) studies. Regardless of the concentration of the photoinitiator eosin Y, it discolored completely upon illumination. Three types of cotton fabrics were compared as antimicrobial materials against Bacillus cereus. One of the fabrics was dyed with a first-generation PAMAM dendrimer which had been functionalized with eight 1,8-naphthalimide fluorophores. Another fabric was dyed with a dendrimer–copper complex, and the third was treated by conversion of the complex into copper nanoparticles encapsulated into the dendrimer. An enhancement in the antimicrobial activity of the textiles was achieved at higher dendrimer concentrations, under illumination with visible light. The fabric modified with the copper nanoparticles encapsulated inside the dendrimer exhibited the best antibacterial activity because it had two photosensitizers (PS), as both 1,8-naphthalimide fluorophores and copper nanoparticles were contained in the dendrimer molecules. The presence of oxygen and suitable illumination activated the photosensitizers to generate the reactive oxygen species (singlet oxygen (1O2) and other oxygenated products, e.g., anion radicals, hydroxyl radicals, and hydrogen peroxide) responsible for destroying the bacteria.

Giving Improved and New Properties to Fibrous Materials by Surface Modification

“…The authors of [122,123] presented a methodology for modifying textile materials with dendrimers containing metal nanoparticles. It was shown in [123] that encapsulation of copper nanoparticles in a dendrimer increased the antimicrobial activity.…”

Integration of Hybrid Dendrimers and Their Generations for Modulated Spatio‐Temporal Action

“…Formation of copper sulfide dendrimers is carried out in two steps, first complexation of the dendrimers containing ethylenediamine core, tertiary nitrogen in the inner layers (exhibiting good solubility) and tris(hydroxymethyl)aminomethane at periphery followed by immobilization. [ 29 ] Application of conventional PAMAM dendrimers with 1,8‐naphthalimides (OD 600 is 52.5%) in textile industries is attributable to its enhanced antimicrobial activities especially against Bacillus cereus on incorporation of reduced copper nanoparticles resulting in Cu‐PAMAM dendrimers nanoparticles with 1,8‐naphthalimides (OD 600 is 37%). [ 30 ]…”

Enhancing the antibacterial activity of PAMAM dendrimer modified with 1,8‐naphthalimides and its copper complex via light illumination

“…bioeffects 10–14 . On the other hand, depending on the nature of the electron‐donor substituents in the naphthalene nucleus, they can absorb light energy and emit it as fluorescence in a wide spectral range, what facilitates their usage as PSs for photodynamic deactivation of pathogens 15–17 …”

“…[10][11][12][13][14] On the other hand, depending on the nature of the electron-donor substituents in the naphthalene nucleus, they can absorb light energy and emit it as fluorescence in a wide spectral range, what facilitates their usage as PSs for photodynamic deactivation of pathogens. [15][16][17] The highly branched structure of dendrimers and their unique properties have been attracting scientists' interest in viewing their antibacterial potential against various pathogenic microorganisms. [18][19][20][21] Depending on the concentration of dendrimers, the permeability of the cell membrane can be altered or denatured.…”