Transport of nanoparticles across an in vitro model of the human intestinal follicle associated epithelium

An in vitro model of the human follicle associated epithelium (FAE) was characterized and the influence of nanoparticle properties on the transcellular transport across the in vitro model was investigated. The model was established by co-culturing Caco-2 and Raji cells, with Caco-2 cells alone as control. The conversion of Caco-2 cells to follicle associated epithelium (FAE) like cells was monitored by following the surface expression of β1-integrins (immunofluorescence) and nanoparticle transport (flow cytometry). The influence of the nanoparticle concentration at the apical side, temperature, size and surface properties of nanoparticles on transport was evaluated, as well as the influence of transport conditions. The conversion of Caco-2 cells into FAE-like cells occurred. The transport was concentration, temperature and size-dependent. Aminated nanoparticles were more efficiently transported than carboxylated nanoparticles, suggesting a role of nanoparticle surface functional groups and hydrophobicity, possibly leading to a different pattern of protein adsorption at their surface. In conclusion, this in vitro model is a promising tool to study the role of M cells in transintestinal nanoparticle transport, as well as to evaluate new drug delivery systems.