Characterization and Cytotoxic Evaluation of Silver and Gold Nanoparticles Produced with Aqueous Extract of Lavandula dentata L. in Relation to K-562 Cell Line

Abstract Metallic nanoparticles have great potential as a chemotherapeutic agent. The aim of this study was to develop and characterize silver and gold nanoparticles using a simple method, as well as evaluating the potential cytotoxic activity in relation to the K-562 cell line. For the synthesis, a solution containing the metallic ions was subjected to magnetic stirring with the aqueous extract of Lavandula dentata L. and a change of colour was observed. With the data obtained from the analyses we concluded that the nanoparticles were successfully obtained by a simple and green method using the aqueous extract of L. dentata. The obtained nanoparticles presented a reduced size, a low level of polydispersion, and a homogenous spherical shape. The nanoparticles presented intense and characteristic diffraction peaks, which could be correlated to the planes of the centred cubic structure of the silver and gold. The two formulations presented predominantly crystalline characteristics. The infrared analysis suggested that the amides and alcohols present in the samples may have been responsible for the reduction and limitation of the size and dispersion of the silver and gold nanoparticles. The cytotoxic assay showed that the nanoparticles demonstrated great potential to reduce the cell viability of the K-562 cell line, especially the gold nanoparticles.

Ecotoxicidad de nanopartículas metálicas y superparamagnéticas de óxido de hierro en dos especies / Ecotoxicity of metalic and superparamagnetics iron oxide nanoparticles in two species

Introducción: la nanotecnología y el empleo de materiales a nano escala son un área relativamente nueva de la ciencia y la tecnología con un gran crecimiento en el mercado global. Muchos de los productos no cuentan con estudios que garanticen su uso seguro, tanto para el hombre como para los ecosistemas. Los estudios ecotoxicológicos permiten evaluar los efectos de un determinado xenobiótico sobre especies representativas de los diferentes compartimentos ambientales. Objetivo: evaluar los efectos tóxicos de nanopartículas de Ag, Au, Ag/Ag y superparamagnéticas de óxido de hierro, en dos especies bioindicadoras de los ecosistemas terrestre y acuático. Métodos: como parte de los estudios de seguridad se realizaron ensayos de toxicidad aguda por contacto en lombriz de tierra de la especie Eisenia andrei, con una duración de 96 horas y estudios en anfibios de la especie Osteopillus septentrionales en diferentes etapas del desarrollo (embrionario y larval). Se evaluó la ocurrencia de mortalidad y de efectos tóxicos, en el caso del ensayo en lombriz de tierra; se determinó además la viabilidad celular. Resultados: los efectos tóxicos más significativos en el caso de la lombriz de tierra fueron, la ocurrencia de alteraciones fisiológicas y conductuales al ser expuesta a NPs de Ag de 3 nm y superparamagnéticas de óxido de hierro, estas últimas provocaron citotoxicidad a la concentración 1,38 mg/mL. En el caso de los anfibios se evidenció toxicidad en NPs de Ag 3 nm y superparamagnéticas de óxido de hierro. Conclusiones: todas las nanopartículas mostraron efectos tóxicos en las especies bioindicadoras evaluadas(AU)

Introduction: Nanotechnology and the use of nanoscale materials are a relatively new area of science and technology with big growth in the global market. Many of these products don't have studies that guarantee their safe use, both for man and for ecosystems. Ecotoxicological studies allow the evaluation of the effects of a particular xenobiotic on representative species of the different environmental compartments. Objective: To evaluate the toxic effects of nanoparticles of Ag, Au, Ag / Ag and super paramagnetic iron oxide in two bioindicators of terrestrial and aquatic ecosystems. Methods: Acute contact toxicity tests were carried out on ground worm of the Eisenia andrei species, with a duration of 96 hours and studies on amphibians of the species Osteopillus septentrionales at different stages of development (embryonic and larval). The occurrence of mortality and toxic effects was evaluated in the case of earthworm test; cell viability was also determined. Results: The most significant toxic effects in the case of earthworms were the occurrence of physiological and behavioral alterations when exposed to 3 nm Ag of superparamagnetic iron oxide nanoparticles, where the latter caused cytotoxicity at concentration of 1.38 mg / mL. In the case of amphibians, toxicity was evidenced in Ag 3 nm nanoparticles and superparamagnetic iron oxide. Conclusions: All nanoparticles showed toxic effects in the evaluated bioindicator species(AU)

Synthesis of Copper Precursor, Copper and its oxide Nanoparticles by Green Chemical Reduction Method and its Antimicrobial Activity.

The present investigation reports, the novel synthesis of Copper and Copper oxide nanoparticles using Chemical reduction method and its physicochemical characterization. The nanoparticles have been prepared using Copper (II) succinate as precursor. Copper nanoparticles are initially formed and subsequently oxidized to copper oxide. As reported the nanoparticles were characterized by UV–visible spectroscopy, Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction measurements (XRD) and scanning electron microscopy (SEM). SEM analysis exhibited nanoparticles with an average diameter of about 45nm. XRD analysis revealed broad pattern of fcc crystal structure of copper metal and cubic cuprites structure for Cu2O. The antimicrobial properties of copper nanoparticles were investigated using Streptococcus pyogenes, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. The bactericidal effects of copper nanoparticles were studied based on diameter of inhibition zone in disk diffusion tests of nanoparticles dispersed in batch cultures. The copper nanoparticles showed excellent activity against Escherichia coli and Staphylococcus aureus, with excellent inhibition zones of 14 mm and 10 mm, respectively. Bacterial sensitivity to nanoparticles was found to vary depending on the microbial species.