Following up on our recent Nanowerk Spotlight on nanofoods, new research shows that consumers could be exposed to nanoparticles in food by a much larger degree than has been expected so far. For a modern consumer it is hard to avoid titanium dioxide (TiO2) - a widely used additive in food, personal care and other household products. Approximately 7 million tons of bulk TiO2 are produced annually and used as white pigment in order to provide whiteness and opacity to foods and other products. Many applications of titanium dioxide would benefit from smaller primary particle sizes, and we can expect the percentage of TiO2 that is produced in or near the nano range to increase.
In a project funded by the Danish Environemntal Protection Agency, researchers have initiated the development of a screening tool called NanoRiskCat for the evaluation of exposure and hazard of nanomaterials contained in products for professional and private use. The project's aim was to identify, categorize and rank the possible exposure and hazards associated with a nanomaterial in a product. NanoRiskCat is using a stepwise approach based on existing data on the conventional form of the chemical as well as the data that may exist on the nanoform. However, the tool still needs to be further validated and tested on a series of various nano products in order to adjust and optimize the concept and thereby to achieve a screening tool as informative and practical as possible.
Early detection of food borne pathogenic bacteria is critical to prevent disease outbreaks and preserve public health. This has led to urgent demands to develop highly efficient strategies for isolating and detecting this microorganism in connection to food safety, medical diagnostics, water quality, and counter-terrorism. Conventional techniques to detect E. coli and other pathogenic bacteria are time-consuming, labor-intensive, and inadequate as they lack the ability to detect bacteria in real time. Thus, there is an urgent need for alternative platforms for the rapid, sensitive, reliable and simple isolation and detection pathogens. Taking a novel approach to isolating pathogenic bacteria from complex clinical, environmental and food samples, researchers have developed a nanomotor strategy that involves the movement of lectin-functionalized microengines. Receptor-functionalized nanoswimmers offer direct and rapid target isolation from raw biological samples without preparatory and washing steps.
Naturally occurring nanomaterials can be found everywhere in nature and only with recent advances in instrumentation and metrology equipment are researchers beginning to locate, isolate, characterize and classify the vast range of their structural and chemical varieties. Scientists are beginning to recognize that all sources of nanomaterials are important in evaluating the possible impact of nanoscale materials on human health and the environment; however, perhaps the greatest benefit to studying these materials will be in their ability to inform researchers about the manner in which nano-sized materials have been a part of our environment from the beginning.
Colloidal silver is not a health elixir and should not be taken orally. Still, dubious online resources that sell silver dispersions or explain how to synthesize colloidal silver for nutritional purposes keep propagating mystic health effects of nano-silver. Whoever considers to "treat" themselves by taking colloidal silver certainly don't know what they want to treat themselves for. They should be aware that drinking an antimicrobial agent at any effectual dosage must inevitably cause harm to innumerable bacteria that are vital to our organism - especially in the alimentary canal. Drinking colloidal silver will either be noneffective or harmful. It is not medicine.
With the mass production of engineered nanoparticles, risk assessment efforts are in need of platforms that offer predictive value to human health and environment, and also possess high throughput screening capacity. Scientists, when turning to a model-organism to help answer genetic questions that cannot be easily addressed in humans, often chose the zebrafish. However, the current screening process in zebrafish involves mostly counting the survival rate, hatching and developmental abnormalities etc. through visual examination of each embryo and/or larvae under a dissecting microscope. Such process is time-consuming, labor-intensive and has limitations on data acquisition as well as statistics analysis. Researchers have now successfully demonstrated two high content imaging platforms to enhance the ability to screen the toxicological effects of nanoparticles in zebrafish embryos.
Until more information becomes available on the mechanisms underlying nanomaterial toxicity, it is uncertain what measurement technique should be used to monitor exposures in the workplace. Many of the sampling techniques that are available for measuring airborne nano aerosols vary in complexity but can provide useful information for evaluating occupational exposures with respect to particle size, mass, surface area, number concentration, and composition. Unfortunately, relatively few of these techniques are readily applicable to routine exposure monitoring. That's why researchers have now developed a unique new sampler design that collects nanoparticles separately from larger particles in a way that mimics the respiratory system.
There is a growing body of research on using carbon nanotubes (CNTs) and other nanomaterials in neural engineering. Scientists are already exploring the feasibility of using CNTs to probe neural activity. With this research comes the need to develop a unified approach when assessing the toxicity of CNT in neurons. However, a complex picture emerges from the reported data: is it feasible to develop CNT-based devices as drug delivery vectors? Ultimately, are soluble CNT neurotoxic, and, if yes, to what degree? Given the often conflicting results of research reports on the biocompatibility of soluble CNT when administered to neurons in the central nervous system, a review article helps to clarify which aspects (technical or methodological) of these studies may be responsible for their heterogeneous conclusions.