Surface coating determines the inflammatory potential of magnetite nanoparticles in murine renal podocytes and mesangial cells

Drug-induced nephrotoxicity is a frequent adverse event and a dose-limiting factor in patient treatment and is a leading cause of prospective drug attrition during pharmaceutical development. Despite the obvious benefits of nanotherapeutics in healthcare strategies, the clearance of imaging agents and nanocarriers from the body following their therapeutic or diagnostic application generates concerns about their safety for human health. Considering the potency of nanoparticles and their massive utilization in biomedicine the impact of magnetic nanoparticles (MNPs) on cells forming the filtration apparatus of the kidney was studied. Using primary mouse renal glomerular podocytes and mesangial cells, we investigated their response to exposure to magnetic nanoparticles coated with polyethylene glycol and bovine serum albumin. Cultured podocytes were more sensitive to MNPs than mesangial cells displaying signs of cell damage and stronger inflammatory response. Both types of MNPs induced the remodeling of actin fibers, affected the cell shape and triggered expression of inflammatory cytokines TNFα and IL-6 in podocytes. On the other hand, iNOS was induced in both renal cell types but only by MNPs with a polyethylene glycol coating. Our results have revealed that the type of cell and the type of nanoparticle coating might be the strongest determinants of cellular response toward nanoparticle exposure. Differences in susceptibility of cells to MNPs might be evident also between neighboring renal cell subpopulations integrally forming functional sub-units of this organ.