Sep 7, 2010
Nanoparticles disrupt human cell line
Researchers at the Georgia Institute of Technology, US, are studying the exposure impacts of manufactured nanomaterials on human cell lines. The goal is to establish prototype evaluation methods for nanotechnology risk assessment and to determine the relationship between nanoscale properties and toxicological effects.
Cell model: before and after exposure to hematite nanoparticlesCell model: before and after exposure to hematite nanoparticles
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.
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.
About the author
The study was conducted by research teams from the School of Civil and Environmental Engineering (CEE) at Georgia Institute of Technology and the School of Life Science (SOLS) at Arizona State University. Wen Zhang is a PhD student at CEE. He performed the exposure test experiments and atomic force microscopy analysis. His advisor, Prof. Yongsheng Chen, leads the projects, which are partially funded by EPA and SRC. Prof. Chen's group is currently focusing on the evaluation of the environmental behaviour, biological impacts and nano-bio interactions of manufactured nanomaterials. Studies are carried out at cellular, genetic and molecular levels; techniques used include AFM, KFM, TEM, SEM, DLS and ICP-MS. Madhavi Kalive is a PhD student at SOLS at ASU. She performed the immunocytochemical staining, confocal microscopy and scanning microscopy analysis of the exposed cell lines. Her advisor, Prof. David G Capco, is a co-PI of the EPA project and contributes expertise in cell biology and bioimaging technology.