Biocompatibility enhancement of graphene oxide-silver nanocomposite by functionalisation with polyvinylpyrrolidone.

Several materials such as silver are used to enhance graphene oxide (GO) sheets antimicrobial activity. However, these toxic materials decrease its biocompatibility and hinder its usage in many biological applications. Therefore, there is an urgent need to develop nanocomposites that can preserve both the antimicrobial activity and biocompatibility simultaneously. This work highlights the importance of functionalisation of GO sheets using Polyvinylpyrrolidone (PVP) and decorating them with silver nanoparticles (AgNPs) in order to enhance their antimicrobial activity and biocompatibility at the same time. The structural and morphological characterisations were performed by UV-Visible, Fourier transform infrared (FTIR), and Raman spectroscopic techniques, X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HR-TEM). The antimicrobial activities of the prepared samples against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans were studied. The cytotoxicity of prepared materials was tested against BJ1 normal skin fibroblasts. The results indicated that the decoration with AgNPs showed a significant increase in the antimicrobial activity of GO and FGO sheets, and functionalisation of GO sheets and GO-Ag nanocomposite with PVP improved the cell viability about 40 and 35%, respectively.

Interaction of nanoclay-reinforced packaging nanocomposites with food simulants and compost environments.

The production of engineered nanomaterials (ENMs) has increased exponentially over the last few decades. ENMs, made from use of engineered nanoparticles (ENPs), have been applied to the food, agriculture, pharmaceutical, and automobile industries. Of particular interest are their applications in packaging nanocomposites for consumer and non-consumer goods. ENPs in nanocomposites are of interest as a packaging material because they reduce the amount of polymer needed, while improving the physical properties. However, the transformation of ENPs in nanocomposite production, their fate, and their toxicity remain unknown while in contact with the package content or after the end of life. The objectives of this chapter are (a) to provide an overview of the main nanoclays used in packaging; (b) to categorize the main polymeric packaging nanocomposites; (c) to provide an overview of the fate and mass transport of ENPs, especially nanoclays; (d) to describe the mass transfer of nanoclays in food simulants and in compost environments; and (e) to identify current and future research needs.

Reflexões bioéticas acerca da inovação em Nanomedicamentos / Reflexiones bioéticsa acerca de la innovación en Nanomedicamentos / Bioethical Reflections on Innovation in Nanomedicines / Reflexions bioètiques sobre la innovació en nanomedicaments

A nanotecnologia vem se desenvolvendo de forma exponencial na área farmacêutica, prometendo grandes benefícios, entretanto, pode estar sujeita a riscos intrínsecos relacionados a esta ciência. Neste artigo é realizada uma reflexão acerca dos desafios enfrentados pelos órgãos regulatórios em função da ausência, ou ainda, incipiente legislação, especialmente no Brasil, visto que os documentos disponíveis em relação a regulamentação, não incluem especificações para nanomedicamentos, os quais apresentam alterações na dimensão e constituição, e consequentemente comportamento diferente de medicamentos convencionais. A contingência envolvendo o desenvolvimento de nanomedicamentos e a gestão dos riscos para a vida humana e o meio ambiente fazem com que a bioética seja invocada de forma a analisar quais os impactos decorrem deste proceso

Nanotechnology has been developing exponentially in the pharmaceutical area, promising great benefits, however, it may be subject to intrinsic risks related to this science. In this article, a reflection is made on the challenges faced by regulatory agencies due to the absence or incipient legislation, especially in Brazil, since the available documents in relation to regulation do not include specifications for nanomedicine, which present changes in the dimension and constitution, and consequently different behavior of conventional drugs. The contingency involving the development of nanomedicine and the management of the risks for human life and the environment, cause bioethics to be invoked in order to analyze the impacts of this process

La nanotecnología se está desarrollando de forma exponencial en el área farmacéutica, prometiendo grandes beneficios, sin embargo, puede estar sujeta a riesgos intrínsecos relacionados a esta ciencia. En este artículo se reflexiona sobre los desafíos enfrentados por los órganos regulatorios en función de la ausencia, o aún incipiente legislación, especialmente en Brasil, ya que los documentos disponibles en relación a la reglamentación, no incluyen especificaciones para nanomedicamentos, los cuales presentan alteraciones en la dimensión y la constitución, y consecuentemente un comportamiento diferente de los medicamentos convencionales. La contingencia que involucra el desarrollo de nanomedicamentos y la gestión de los riesgos para la vida humana y el medio ambiente hacen que la bioética sea invocada para analizar qué impactos se derivan de este proceso

La nanotecnologia s'està desenvolupant de forma exponencial en l'àrea farmacèutica, prometent grans beneficis; no obstant això, pot estar subjecta a riscos intrínsecs relacionats amb aquesta ciència. En aquest article es reflexiona sobre els desafiaments que enfronten els òrgans reguladors en funció de l'absència, o d’una legislació incipient, especialment al Brasil, ja que els documents disponibles en relació a la reglamentació no inclouen especificacions per a nanomedicaments, els quals presenten alteracions en la seva dimensió i constitució, i conseqüentment presenten un comportament diferent al dels medicaments convencionals. La contingència que involucra el desenvolupament de nanomedicaments i la gestió dels riscos per a la vida humana i el medi ambient fan que la bioètica hagi de jugar un paper a fi d’analitzar quins impactes es deriven d'aquest procés

Mechanically adaptive intracortical implants improve the proximity of neuronal cell bodies.

The hypothesis is that the mechanical mismatch between brain tissue and microelectrodes influences the inflammatory response. Our unique, mechanically adaptive polymer nanocomposite enabled this study within the cerebral cortex of rats. The initial tensile storage modulus of 5 GPa decreases to 12 MPa within 15 min under physiological conditions. The response to the nanocomposite was compared to surface-matched, stiffer implants of traditional wires (411 GPa) coated with the identical polymer substrate and implanted on the contralateral side. Both implants were tethered. Fluorescent immunohistochemistry labeling examined neurons, intermediate filaments, macrophages, microglia and proteoglycans. We demonstrate, for the first time, a system that decouples the mechanical and surface chemistry components of the neural response. The neuronal nuclei density within 100 µm of the device at four weeks post-implantation was greater for the compliant nanocomposite compared to the stiff wire. At eight weeks post-implantation, the neuronal nuclei density around the nanocomposite was maintained, but the density around the wire recovered to match that of the nanocomposite. The glial scar response to the compliant nanocomposite was less vigorous than it was to the stiffer wire. The results suggest that mechanically associated factors such as proteoglycans and intermediate filaments are important modulators of the response of the compliant nanocomposite.