Graphene nanocomposite for biomedical applications: fabrication, antimicrobial and cytotoxic investigations

Abstract

Materials possessing excellent bacterial toxicity, while presenting low cytotoxicity to human cells, are strong candidates for biomaterials applications. In this study, we present the fabrication of a nanocomposite containing poly(N-vinylcarbazole) (PVK) and graphene (G) in solutions and thin films. Highly dispersed PVK-G (97-3 w/w%) solutions in various organic and aqueous solvents were prepared by solution mixing and sonication methods. The thermal properties and morphology of the new composite were analyzed using thermal gravimetry analysis (TGA) and atomic force microscopy (AFM), respectively. PVK-G films were immobilized onto indium tin oxide (ITO) substrates via electrodeposition. AFM was used to characterize the resulting topography of the nanocomposite thin films, while cyclic voltammetry and UV-vis were used to monitor their successful electrodeposition. The antimicrobial properties of the electrodeposited PVK-G films and solution-based PVK-G were investigated against Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis). Microbial growth after exposure to the nanocomposite, metabolic assay and live-dead assay of the bacterial solutions exposed to PVK-G presented fewer viable and active bacteria than those exposed to pure PVK or pure graphene solutions. The PVK-G film inhibited about 80% of biofilm surface coverage whereas the PVK- and G-modified surfaces allowed biofilm formation over almost the whole coated surface (i.e. > 80%). The biocompatibility of the prepared PVK-G solutions on NIH 3T3 cells was evaluated using the MTS cell proliferation assay. A 24 h exposure of the PVK-G nanocomposite to the NIH 3T3 cells presented ~80% cell survival.

Graphene Oxide as Antimicrobial Against Two Gram-Positive and Two Gram-Negative Bacteria in Addition to One Fungus

“…Also it has been used as a promising material for preparing new composites (Tang et al, 2013). It is well known that GO and its composites possess anti-microbial properties and have been used as anti-bacterial and antifungal agents (Santos et al, 2012;De Faria et al, 2014).…”

Bionanocompuestos de quitosano-óxido de grafeno: una alternativa novedosa para la conservación de alimentos

“…El óxido de grafeno fue preparado por un método modificado de Hummers como se reportó previamente (Santos et al, 2012). Las películas de quitosano se prepararon de acuerdo con el método reportado por Shao et al (2013), modificando la temperatura de entrecruzamiento de 100 a 120ºC únicamente, y adicionando la cantidad necesaria de óxido de grafeno para completar concentraciones de 0,1, 0,25, 0,4 y 0,6% (p/p) respecto al quitosano.…”

“…La caracterización se llevó a cabo por espectroscopía de infrarrojo (datos sin publicar) (espectrómetro Agilent Cary 680 FTIR) y se determinaron las propiedades mecánicas con un analizador mecánico (Shimadzu EZ-LX, Japan), bajo la norma ASTM D882-12. Finalmente, las propiedades antimicrobianas fueron determinadas con ayuda de un microscopio de fluorescencia, mediante el método de conteo de células vivas y muertas (Santos et al, 2012). El espesor de las películas fue determinado usando un micrómetro digital Mitutoyo Digimatic.…”

“…Un gran reto que permanece aún presente es lograr una excelente dispersión y compatibilidad de los nanorellenos dentro de la fase continua polimérica (Rhim et al, 2013). Los nanocompuestos son mezclas de polímeros con aditivos orgánicos e inorgánicos que tiene al menos una dimensión en la escala nanométrica, con diferentes geometrías (esferas, fibras, partículas), que generan un incremento en el rendimiento de las propiedades mecánicas, de barrera frente a diversos gases y solventes, además de disminuir la densidad, mejorar la transparencia, flujo y la posibilidad de ser reutilizados, brindando grandes ventajas frente a los materiales compuestos o a los polímeros puros (Alexandre & Dubois, 2000;Santos et al, 2012;Giannelis, 1996;S. Sinha Ray & Okamoto, 2003).…”

Electrochemical synthesis of nanosized hydroxyapatite/graphene composite powder

“…The antimicrobial properties of graphenebased materials have been thoroughly evaluated by many researchers [22][23][24][25]. The antibacterial activity of graphene oxide and graphene is attributed to the significant membrane stress induced by the sharp edges of their nanosheets, which may result in physical damage to cell membranes, leading to the loss of bacterial membrane integrity and the leakage of RNA [25,26].…”