Integrating physiologically-inspired nanoparticles with intestinal cell co-culture for enhanced activity profiling of food constituents and contaminants in vitro

Development of innovative in vitro test methods for the detection of potential health risks related to contaminants is imperative to food safety. Here we present an extended implementation for the intestinal model based on the human Caco-2/HT29-MTX-E12 co-culture which produces mucus and exhibits barrier function when differentiated. To simulate the presence of the microbiome, SiO₂-based mesoporous rod-shaped nanoparticles (bacteria-like; bacNPs, 200 × 450 nm) were included adding an extra dimension to the system. Smaller SiO₂-based mesoporous rod-shaped nanoparticles (srNPs, 35 × 160 nm) were used to mimic particulate matter present in the intestine as for the chyme transit. Synthetized and utilized to reproduce elements of the intestinal lumen, nanorods supported testing the interaction with the intestinal cells and mucus at the nanoscale. To start exploring the applicability of the model, the mycotoxin fumonisin B₁ (10-100 μM) produced by Fusarium spp. was chosen as a test substance due to its wide occurrence and hazardous potential. As fumonisins are known to hamper lipid metabolism, palmitic acid (25-100 μM) - one of the most prevalent fatty acids in our diets - was additionally used. Significantly for the reproduction of in vivo physiology, srNPs penetrated through the mucus layer resulting in the modulation of intercellular distances and paracellular permeability in conjunction with exposure to fumonisin B₁. This enabled the quantification of a response which was not detectable using exclusively the Caco-2/HT29-MTX-E12 model and paves the way toward the creation of systems that more efficiently support the screening of food contaminants in vitro.