Inorganic nanoparticles and biology

Biocompatibilitat, biodistribució, biodegradació, inflamació i interferència amb el funcionament normal de les cèl·lules i teixits, entre d'altres, determinarà la toxicitat de les nanopartícules inorgàniques i nanoestructures de carbó, i per tant l'extensió del seu us. Exemples recents a la literatura científica mostren que les nanopartícules inorgàniques i els nanotubs de carboni no causen efectes tòxics aguts. De totes maneres, la interacció d'aquests materials amb organismes vius pot pertorbar la seva activitat normal induint funcionaments erronis i malalties. De fet, les interaccions entre nanopartícules i biologia que s'han observat, que poden ser usades per detectar i manipular estats biològics i contribuir a una millor diagnosis i teràpia, també podrien tenir un impacte negatiu en la salut i el medi ambient si s'alliberen incontroladament quantitats massives d'alguns tipus de nanopartícules, abans que es faci una avaluació exhaustiva dels riscos potencials d'aquests nous materials. La pregunta clau és si els riscos desconeguts de les nanoparticules, en particular el seu impacte en la salut i el medi ambient, supera els beneficis d'aquesta tecnologia en societat. Per això, pel futur desenvolupament de la nanotecnologia, l'avaluació de la seva potencial toxicitat es clau.Biocompatibility, biodistribution, biodegradation, inflammation and interference with the normal functioning of cells and tissues are some of the features that determine the toxicity of engineered inorganic nanoparticles and carbon nanostructures, and therefore the potential extent of their use. Recent examples in the literature show that engineered inorganic nanoparticles and carbon nanostructures do not normally cause acute toxic effects. However, their interaction with living organisms may disrupt normal activity leading to disordersand disease. Nanoparticle-organism interactions, which can be used to detect and manipulate biological states and to heal damaged organs in an environment controlled by specialists, as in clinical cases, could lead to environmental and human health hazards if nanoparticles are released prior to adequate risk assessment and without proper controls. The central question is whether the unknown risks of engineered nanoparticles, in particular their impact on health and the environment, outweigh their established benefits for society. Therefore, to accurately evaluate the utility of these materials it is necessary to assess their potential toxicity

Nanoparticles for cosmetics: how safe is safe?

[EN]: The increasing use of nanoparticulate engineered materials posses the question on the safety of those materials. A paradigmatic case is their use in cosmetics, in principle because those materials are in direct contact with the body and because probably cosmetic usage of nanotechnology will anticipate the use of nanoparticles in medicine. Non acute toxic effects have been observed so far and some tones of some nanoparticles are already used in sunscreens. However the observed effects of interaction between nanoparticles and biological structures calls for a better understanding of that interaction and a prudent development of consumer products based on nanoparticles. In this paper we summarize the known facts regarding the use of nanoparticles in cosmetics.[CA]: L’ús creixent de materials nanoparticulats qüestiona la seguretat d’aquests. Un cas paradigmàtic és la seva aplicació en cosmètica, en principi degut a què aquests materials estan directament en contacte amb el cos i perquè probablement la utilització de la nanotecnologia en cosmètica s’anticiparà a la utilització de nanopartícules en medicina. Fins el moment present, no s’han observat efectes tòxics aguts, i ja s’estan fent servir quantitats elevades de nanopartícules en protectors solars. No obstant, els efectes observats sobre la interacció entre nanopartícules i estructures biològiques requereix una millor comprensió d’aquesta interacció i un desenvolupament prudent dels productes de consum basats en nanopartícules. En aquest article, resumim els fets coneguts en relació a l’ús de nanopartícules en cosmètica.Peer Reviewe

The Spherical Nucleic Acids mRNA Detection Paradox

&lt;p&gt;From the 1950s onwards, our understanding of the formation and intracellular trafficking of membrane vesicles was informed by experiments in which cells were exposed to gold nanoparticles and their uptake and localisation, studied by electron microscopy.&amp;nbsp; In the last decade, building on progress in the synthesis of gold nanoparticles and their controlled functionalisation with a large variety of biomolecules (DNA, peptides, polysaccharides), new applications have been proposed, including the imaging and sensing of intracellular events. Yet, as already demonstrated in the 1950s, uptake of nanoparticles results in confinement within an intracellular vesicle which in principle should preclude sensing of cytosolic events. To study this apparent paradox, we focus on a commercially available nanoparticle probe that detects mRNA through the release of a fluorescently-labelled oligonucleotide (unquenching the fluorescence) in the presence of the target mRNA. Using electron, fluorescence and photothermal microscopy, we show that the probes remain in endocytic compartments and that they do not report on mRNA level. We suggest that the validation of any nanoparticle-based probes for intracellular sensing should include a quantitative and thorough demonstration that the probes can reach the cytosolic compartment.&lt;/p&gt;</ns7:p

Nanoparticles for cosmetics : how safe is safe?

L'ús creixent de materials nanoparticulats qüestiona la seguretat d'aquests. Un cas paradigmàtic és la seva aplicació en cosmètica, en principi degut a què aquests materials estan directament en contacte amb el cos i perquè probablement la utilització de la nanotecnologia en cosmètica s'anticiparà a la utilització de nanopartícules en medicina. Fins el moment present, no s'han observat efectes tòxics aguts, i ja s'estan fent servir quantitats elevades de nanopartícules en protectors solars. No obstant, els efectes observats sobre la interacció entre nanopartícules i estructures biològiques requereix una millor comprensió d'aquesta interacció i un desenvolupament prudent dels productes de consum basats en nanopartícules. En aquest article, resumim els fets coneguts en relació a l'ús de nanopartícules en cosmètica.The increasing use of nanoparticulate engineered materials posses the question on the safety of those materials. A paradigmatic case is their use in cosmetics, in principle because those materials are in direct contact with the body and because probably cosmetic usage of nanotechnology will anticipate the use of nanoparticles in medicine. Non acute toxic effects have been observed so far and some tones of some nanoparticles are already used in sunscreens. However the observed effects of interaction between nanoparticles and biological structures calls for a better understanding of that interaction and a prudent development of consumer products based on nanoparticles. In this paper we summarize the known facts regarding the use of nanoparticles in cosmetics

Detoxifying antitumoral drugs via nanoconjugation: the case of gold nanoparticles and cisplatin

Nanoparticles (NPs) have emerged as a potential tool to improve cancer treatment. Among the proposed uses in imaging and therapy, their use as a drug delivery scaffold has been extensively highlighted. However, there are still some controversial points which need a deeper understanding before clinical application can occur. Here the use of gold nanoparticles (AuNPs) to detoxify the antitumoral agent cisplatin, linked to a nanoparticle via a pH-sensitive coordination bond for endosomal release, is presented. The NP conjugate design has important effects on pharmacokinetics, conjugate evolution and biodistribution and results in an absence of observed toxicity. Besides, AuNPs present unique opportunities as drug delivery scaffolds due to their size and surface tunability. Here we show that cisplatin-induced toxicity is clearly reduced without affecting the therapeutic benefits in mice models. The NPs not only act as carriers, but also protect the drug from deactivation by plasma proteins until conjugates are internalized in cells and cisplatin is released. Additionally, the possibility to track the drug (Pt) and vehicle (Au) separately as a function of organ and time enables a better understanding of how nanocarriers are processed by the organism.The authors acknowledge financial support from the grants “Plan Nacional” (MAT2009-14734-C02-01 and MAT2009-14734-C02-02) and NANOBIOMED-CONSOLIDER (CSD2006-00012) from the Spanish Government. Also grants VALTEC09-2-0085, VALTEC09-2-0089, and 2009-SGR-776 from the Catalan GovernmentS

Multimodal cell tracking from systemic administration to tumour growth by combining gold nanorods and reporter genes.

Understanding the fate of exogenous cells after implantation is important for clinical applications. Preclinical studies allow imaging of cell location and survival. Labelling with nanoparticles enables high sensitivity detection, but cell division and cell death cause signal dilution and false positives. By contrast, genetic reporter signals are amplified by cell division. Here, we characterise lentivirus-based bi-cistronic reporter gene vectors and silica-coated gold nanorods (GNRs) as synergistic tools for cell labelling and tracking. Co-expression of the bioluminescence reporter luciferase and the optoacoustic reporter near-infrared fluorescent protein iRFP720 enabled cell tracking over time in mice. Multispectral optoacoustic tomography (MSOT) showed immediate biodistribution of GNR-labelled cells after intracardiac injection and successive clearance of GNRs (day 1-15) with high resolution, while optoacoustic iRFP720 detection indicated tumour growth (day 10-40). This multimodal cell tracking approach could be applied widely for cancer and regenerative medicine research to monitor short- and long-term biodistribution, tumour formation and metastasis

Preventing Plasmon Coupling between Gold Nanorods Improves the Sensitivity of Photoacoustic Detection of Labeled Stem Cells in Vivo

© 2016 American Chemical Society.Gold nanorods are excellent contrast agents for imaging technologies which rely on near-infrared absorption such as photoacoustic imaging. For cell tracking applications, the cells of interest are labeled with the contrast agent prior to injection. However, after uptake into cells by endocytosis, the confinement and high concentration in endosomes leads to plasmon band broadening and reduced absorbance. This would limit the potential of multispectral optoacoustic tomography in terms of spectral processing and, consequently, sensitivity. Here, we show that steric hindrance provided by silica coating of the nanorods leads to the preservation of their spectral properties and improved photoacoustic sensitivity. This strategy allowed the detection and monitoring of as few as 2 × 104 mesenchymal stem cells in mice over a period of 15 days with a high spatial resolution. Importantly, the silica-coated nanorods did not affect the viability or differentiation potential of the transplanted mesenchymal stem cells