Figure 9.

Schematic representing the intrinsic biological effects of silica-based nanoparticles on osteoblast differentiation. NP1 is internalized by caveolae-mediated endocytosis, which triggers a signal transduction pathway dependent on ERK1/2. This stimulation of ERK1/2 is necessary for the processing of LC3β form I to the activated form II. NP1 is bound by both LC3 and p62, resulting in the formation of autophagosomes. The stimulation of autophagy is necessary for osteoblast differentiation and mineralization.