Morphological changes in A549 cells resulting from incubation with nano-SiO2.

A series of experiments were performed in which A549 cells were incubated with a variety of concentrations of nano-SiO2 for up to 24 h in medium containing different quantities of serum. The condition of the cells following treatment for different periods of time was assessed by light microscopy. In the absence of nano-SiO2 the cells grew normally with characteristic squamous cell morphology in the form of an adherent monolayer with very few rounded or floating cells (see figure 2). Those cultures that maintained such an appearance are indicated as ‘+’. In those cultures that responded to treatment with nano-SiO2 resulting in any cell abnormalities are indicated as ‘−’ (figure 2). Each set of conditions was replicated 3-times in separate cultures.