Mesoporous silica particles are phagocytosed by microglia and induce a mild inflammatory response .

Mesoporous silica particles (MSPs) are broadly used drug delivery carriers. In this study, the authors analyzed the responses to MSPs of astrocytes and microglia, the two main cellular players in neuroinflammation. Primary murine cortical mixed glial cultures were treated with rhodamine B-labeled MSPs. MSPs are avidly internalized by microglial cells and remain inside the cells for at least 14 days. Despite this, MSPs do not affect glial cell viability or morphology, basal metabolic activity or oxidative stress. MSPs also do not affect mRNA levels of key proinflammatory genes; however, in combination with lipopolysaccharide, they significantly increase extracellular IL-1β levels. These results suggest that MSPs could be novel tools for specific drug delivery to microglial cells.