The scientists have compared Caco-2 cell lines, which simulate human intestinal cells, before and after exposure to hematite nanoparticles (NPs). It is evident that exposure to small hematite NPs (26 nm in diameter) significantly disrupted microvilli and adhesion junctions on the inner cell membrane (see image). The presence of numerous microvilli on the apical surface helps to guide nutrient adsorption, while adhesion junctions give strength to the structural integrity of cell lines.

The study demonstrated that hematite NPs of different sizes had distinct and size-dependent effects on epithelial cells. The knowledge gained from the work is an important step towards assessing the health risk of NPs to the human gastrointestinal tract or digestive system.

AFM analysis

Building on their results, the researchers are now busy exploring the connections between the nanoscale properties (size, shape and surface charge) and biological impacts of nanomaterials. For example, state-of-the-art techniques, such as atomic force microscopy (AFM), are being used to image and quantify these nanoscale properties. The aim is to deepen the understanding of nano-bio interfacial interactions and provide fundamental insights necessary for designing environmentally benign nanomaterials.

Full results can be found in the journal Nanotechnology.