Many natural chemicals in food are in the nanometer size range, and the selective uptake of nutrients with nanoscale dimensions by the gastrointestinal (GI) tract is a normal physiological process. Novel engineered nanomaterials (NMs) can bring various benefits to food, e.g., enhancing nutrition. Assessing potential risks requires an understanding of the stability of these entities in the GI lumen, and an understanding of whether or not they can be absorbed and thus become systemically available. Data are emerging on the mammalian in vivo absorption of engineered NMs composed of chemicals with a range of properties, including metal, mineral, biochemical macromolecules, and lipid‐based entities. In vitro and in silico fluid incubation data has also provided some evidence of changes in particle stability, aggregation, and surface properties following interaction with luminal factors present in the GI tract. The variables include physical forces, osmotic concentration, pH, digestive enzymes, other food, and endogenous biochemicals, and commensal microbes. Further research is required to fill remaining data gaps on the effects of these parameters on NM integrity, physicochemical properties, and GI absorption. Knowledge of the most influential luminal parameters will be essential when developing models of the GI tract to quantify the percent absorption of food‐relevant engineered NMs for risk assessment. WIREs Nanomed Nanobiotechnol 2015, 7:609–622. doi: 10.1002/wnan.1333For further resources related to this article, please visit the WIREs website.

Bovine spongiform encephalopathy (BSE) belongs to a group of progressively degenerative neurological diseases known as transmissible spongiform encephalopathies (TSEs) associated with a variant form of Creutzfeldt-Jakob disease in humans. TSEs are fatal diseases caused by prions (proteinaceous infectious particle) and are characterized by an incubation period that may range from several months to several years, depending on the host. Because BSE is spread through animal feed, the main strategy for preventing the establishment and spread of BSE is to prohibit the use of proteins derived from mammalian tissue in feed for ruminant animals. Enforcement of these regulations relies on the ability to identify the presence of prohibited proteins in ruminant feed. The methods to detect bovine products in rendered and cooked materials are based on analyses of DNA, bone, or protein. In this article, we discuss the current methodology as well as other potentially useful methods of analysis of animal material in food. While methods are generally useful, none specifically distinguish between prohibited bovine material and allowable bovine products, such as milk or blood. Furthermore, all these methods are hampered by the fact that the rendering process involves heat treatment that denatures and degrades proteins and DNA. There is a need for improving existing methods and developing new methods to overcome these two limitations.

This article is one of a series of 4 that report on a task of the NanoRelease Food Additive project of the International Life Science Institute Center for Risk Science Innovation and Application to identify, evaluate, and develop methods that are needed to confidently detect, characterize, and quantify intentionally produced engineered nanomaterials (ENMs) released from food along the alimentary tract. This particular article focuses on the problem of detecting and characterizing ENMs in the various compartments of the alimentary tract after they have been ingested from dietary sources. An in depth analysis of the literature related to oral toxicity of ENMs is presented, paying particular attention to analytical methodology and sample preparation. The review includes a discussion of model systems that can be used to study oral uptake of ENMs in the absence of human toxicological data or other live-animal studies. The strengths and weaknesses of various analytical and sample preparation techniques are discussed. The article concludes with a summary of findings and a discussion of potential knowledge gaps and targets for method development in this area.

An immunoassay system was developed for efficient detection of prohibited meat and bone meal (MBM) in animal feed. Monoclonal antibodies (MAbs) were raised against bovine smooth muscle autoclaved at 130 degrees C for 20 min. Among the 1,500 supernatants of hybridoma cells screened, MAbs 3E1, 1G3, and 3E10 were selected and characterized in this study. The first set of MAbs produced, 3E1 and 1G3, had stronger reactivity against MBM than against smooth muscle that was heat treated at 90 degrees C for 10 min. However, reactivity gradually increased against smooth muscle that was autoclaved at 130 degrees C for up to 1 h. The enzyme-linked immunosorbent assay for detection of MBM in animal feed was optimized with the MAb 3E10 because of its superior performance. MAb 3E10 diluted to 100-fold was used to differentiate bovine MBM from that of other species in ingredients used for commercial animal feeds and could detect down to 0.05% MBM mixed in animal feed.