Fig. 2

Representative immunofluorescence microscopy images showing the morphology of SH-SY5Y cells on day in vitro (DIV) 7, stained with b-3-tubulin (green). Cells were kept undifferentiated (A–D), differentiated with retinoic acid (RA) (E–H) or staurosporine (ST) (I–L). Control images, unexposed to NPs, are shown in A, B and C. SH-SY5Y cells exposed to (2.6 × 10¹⁰ NPs/ml) SiPCL-NPs (red) for 24 h at DIV1 are depicted in B, F and J. SH-SY5Y cells exposed to NPs at DIV4 are shown in C, G and K and exposure at DIV6 in D, H and L. Nuclei are shown in blue. Magnification ×630, scale bar = 50 μm