Fig. 3. (A) Schematic depicting uptake of small (120 nm) and large (360 nm) Cy5-labelled silica particles by A549 on particle-decorated substrates to assess the influence of particle-generated topography on particle internalisation in a competition co-exposure system. Particle-decorated substrates consist of 420 nm BDP-labelled silica electrostatically adsorbed to APTES-modified PDMS 10 : 1 (10 : 1 + PD) and APTES-modified PDMS 40 : 1 (40 : 1 + PD). (B) Transmission electron microscope image of silica particles (dTEM = 420 nm) used to form the particle-decorated (PD). (C) Schematic of PDMS surface functionalization with 3-aminopropyltriethyoxysilane (APTES) to facilitate adsorption of negatively charged silica particles. (D) Scanning electron microscope image of PDMS 10 : 1 and PDMS 40 : 1 treated with APTES and decorated with silica particles (dTEM = 420 nm) to form a particle-decorated surface. Scale bar represents 2 μm.
