Silver nanoparticles incorporated into nanostructured biopolymer membranes produced by electrospinning: a study of antimicrobial activity

Abstract

This study examines the antimicrobial activity of silver nanoparticles incorporated into nanostructured membranes made of cellulose acetate (CA) and blends of chitosan/poly-(ethylene oxide, CTS/PEO) and prepared by electrospinning. The formation of chemically synthesized Ag nanoparticles (AgNPs) was monitored by UV-visible spectroscopy (UV-Vis) and characterized by transmission electron microscopy (TEM). The size distribution of the AgNPs was measured by dynamic light scattering (DLS), with an average size of approximately 20 nm. The presence of AgNPs on the surface of electrospun nanofibers was observed by field emission electron microscopy (FEG) and confirmed by TEM. The antimicrobial activity of AgNPs incorporated into nanostructured membranes made of CA and CTS/PEO electrospun nanofibers was evaluated in the presence of both Gram-positive bacteria, such as Staphylococcus aureus ATCC 29213 and Propionibacterium acnes ATCC 6919, and Gram-negative bacteria, such as Escherichia coli ATCC 25992 and Pseudomonas aeruginosa ATCC 17933. Microbiological results showed that the presence of AgNPs in CA and CTS/PEO nanostructured membranes has significant antimicrobial activity for the Gram-positive bacteria Escherichia coli and Propionibacterium acnes. Uniterms:Electrospinning. Silver nanoparticles/antibacterial activity. Cellulose acetate. Chitosan.Neste trabalho avaliou-se a atividade antimicrobiana das nanopartículas de prata (AgNPs) incorporadas em membranas de acetato celulose (AC) e blendas de quitosana/poli-óxido de etileno (CTS/PEO) preparadas pelo método de eletrofiação. A formação das AgNPs previamente sintetizadas foi monitorada por UV-Vis e caracterizada por microscopia eletrônica de transmissão (MET). A distribuição de tamanho das AgNPs foi mensurada por espalhamento de luz dinâmico, com tamanho médio em torno de 20 nm. A presença das NPs na superfície das nanofibras eletrofiadas foi observada por microscopia eletrônica com emissão de campo (FEG) e confirmada por MET. A atividade antimicrobiana das membranas nanoestruturadas de AC e CTS/PEO foi avaliada pelo uso de bactérias Gram-positivas, tais como Staphylococcus aureus ATCC 29213 e Propionibacterium acnes ATCC 6919, e Gram-negativas, como Escherichia coli ATCC 25992 e Pseudomonas aeruginosa ATCC 17933. Os resultados microbiológicos mostraram a presença das AgNPs nas membranas de AC e CTS/PEO com significativa atividade antimicrobiana para Escherichia coli e Propionibacterium acnes, respectivamente.Unitermos: Eletrofiação. Nanopartículas de prata/atividade antimicrobiana. Acetato de celulose. Quitosana. 912 INTRODUCTIONThe use of metal nanoparticles in various medical and biotechnological applications is one of the most investigated areas in materials science. These applications require appropriate chemical functionalization of the nanoparticles with organic molecules or their incorporation into polymer matrices (Dallas, Sharma, Zboril, 2011). Among the numerous types of nanoparticles that have been used to decorate polymers, silver nanoparticles (AgNPs) ...

Silver nanoparticles biosynthesis and impregnation in cellulose acetate membrane for anti-yeast therapy

“…The distance from the needle to the collector was 10 cm; the applied voltage was 15 kV, and the flow rate was 1 ml h -1 . Membrane samples were collected in aluminium foil used to coat the copper plate during the experiments (Nista et al, 2012;Segala et al, 2015).…”

“…AgNPs present efficient antimicrobial properties compared to other molecules due to their large superficial area that promotes a better contact with the microorganims (Rai et al, 2009;Kon and Rai, 2013). However, according to Segala et al (2015), the antimicrobial activity of AgNPs depends on some factors such as crystallinity, geometry, size, superficial oxidation, agglomeration in the biological environment, superficial charge, groups present in the nanoparticles surface, and others. For that reason, we can deduce that the properties of A. oryzae AgNPs enabled a better interaction with the yeast cells promoting the penetration of the nanoparticles through the plasmatic membrane of the micro-organism causing cell death.…”

“…The colloidal solution of AgNPs can be combined with many polymeric matrices to extend the release of antimicrobial and increase its biocompatibility. The electrospinning nanofibers, for example, are polymers that have high potential of application in pharmaceutical and cosmetic industries for regeneration of skin and organs, therapies of drugs administration and others (Nista et al, 2015;Segala et al, 2015).…”

“…The search for nanostructured polymers with antimicrobial action are increasing due to their great potential of use in devices that require antiseptic characters as applications in skin wounds (Abdelgawad et al, 2013;Segala et al, 2015). For that reason, AgNPs are the nanoforms most used in polymers due to their electronic, optical, catalytic and antimicrobial properties (Segala et al, 2015).…”

“…In these kinds of infections, the nanomembranes also can act like a sponge absorbing all the fluids from the lesion and insure the oxygenation through the porous net of nanofibers (Nista et al, 2013). The cellulose acetate is a polymer that presents good tenacity, high biocompatibility and relative low cost, besides, easily forms pellicles with porous structure, the characters that make it advantageous to build an antiseptic nanocomposite to wounds treatment (Nista et al, 2012;Segala et al, 2015).…”