Lysosomal iron liberation is responsible for the vulnerability of brain microglial cells to iron oxide nanoparticles: comparison with neurons and astrocytes

Thus, detailed knowledge on the accumulation and toxic potential of IONPs for the different types of brain cells is highly warranted. Literature data suggest that microglial cells are more vulnerable towards IONP exposure than other types of brain cells.

To investigate the mechanisms involved in IONP-induced microglial toxicity, we applied fluorescent dimercaptosuccinate-coated IONPs to primary cultures of microglial cells. Exposure to IONPs for 6 h caused a strong concentration-dependent increase in the microglial iron content which was accompanied by a substantial generation of reactive oxygen species (ROS) and by cell toxicity. In contrast, hardly any ROS staining and no loss in cell viability were observed for cultured primary astrocytes and neurons although these cultures accumulated similar specific amounts of IONPs than microglia.