Human epithelial cells in vitro – Are they an advantageous tool to help understand the nanomaterial-biological barrier interaction?
AbstratThe human body can be exposed to nanomaterials through a variety of different routes. As nanomaterials get in contact with the skin, the gastrointestinal tract, and the respiratory tract, these biological compartments are acting as barriers to the passage of nano-sized materials into the organism. These structural and functional barriers are provided by the epithelia serving as an interface between biological compartments. In order to initiate the reduction, refinement and replacement of time consuming, expensive and stressful (to the animals) in vivo experimental approaches, many in vitro epithelial cell culture models have been developed during the last decades. This review therefore, focuses on the functional as well as structural aspects of epithelial cells as well as the most commonly used in vitro epithelial models of the primary biological barriers with which nanomaterials might come in contact with either occupationally, or during their manufacturing and application. The advantages and disadvantages of the different in vitro models are discussed in order to provide a clear overview as to whether or not epithelial cell cultures are an advantageous model to be used for basic mechanism and nanotoxicology research.