Measurement Methods for the Oral Uptake of Engineered Nanomaterials from Human Dietary Sources: Summary and Outlook

Abstract

This article is one of a series of 4 that report on a task of the NanoRelease Food Additive (NRFA) project of the International. Life Science Institute Center for Risk Science Innovation and Application. The project aims are 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 offers an overview of the NRFA project, describing the project scope and goals, as well as the strategy by which the task group sought to achieve these goals. A condensed description of the general challenge of detecting ENMs in foods and a brief review of available and emerging methods for ENM detection is provided here, paying particular attention to the kind of information that might be desired from an analysis and the strengths and weaknesses of the various approaches that might be used to attain this information. The article concludes with an executive summary of the task group's broad findings related to the 3 topic areas, which are covered in more detail in 3 subsequent articles in this series. The end result is a thorough evaluation of the state of ENM measurement science specifically as it applies to oral uptake of ENMs from human dietary sources.

The role of the food matrix and gastrointestinal tract in the assessment of biological properties of ingested engineered nanomaterials (iENMs): State of the science and knowledge gaps

“…Thus, it is possible to measure their initial particle size distribution, shape, composition, surface chemistry, and surface charge using conventional methods (Singh et al , 2014; Szakal et al , 2014a; Szakal et al , 2014c). However, these intrinsic ENM properties may change considerably when the nanoparticles encounter the complex environment of the human GIT.…”

“…Knowledge of the impact of ingested ENM characteristics on their GI fate is currently rather limited. In addition, there is a lack of standardized protocols and methodologies to assess the GI fate of ingested engineered nanomaterials (iENMs), and their potential toxicity (Contado, 2015; Szakal et al , 2014a; Szakal et al , 2014c). …”

Standardization of Nanoparticle Characterization: Methods for Testing Properties, Stability, and Functionality of Edible Nanoparticles

“…Assessment of the potential toxicity of nanoparticles within the human body also depends on understanding their gastrointestinal fate after ingestion. A number of analytical approaches have therefore been developed to establish the potential gastrointestinal fate of nanoparticles (Dahan and Hoffman, 2008;Li et al, 2011;McClements and Li, 2010a;Szalal et al, 2014;Williams et al, 2012).…”

“…For example, hydrophobic protein (zein) nanoparticles that have been converted into a powdered form by spray drying can simply be dispersed in water prior to analysis . For nanoparticles dispersed within semi-solid food matrices, this may be achieved using mechanical devices (such as high speed blenders), chemical treatments (such as acid or alkali), and/or enzyme treatments (such as proteases, amylases, or lipases) (Szakal et al, 2014;Szalal et al, 2014). Chemical or enzymatic treatments may also be useful for breaking down other types of particles or polymer in the matrix (provided they do not alter the properties of the nanoparticles being analyzed).…”

Utility of models of the gastrointestinal tract for assessment of the digestion and absorption of engineered nanomaterials released from food matrices

“…Require validated and standardized models and analytical tools for the detection of NMs in food, complex media, chyme and feces, as well as within cells and tissues of the GI tract Assess reliability of analytical digestion and detection for routine use (e.g. Szakal et al, 2014b). Radiolabeled materials have been used more reluctantly used in recent years, but these may need to be applied to answer scientific uptake questions.…”