Presence of glucose-coated gold nanoparticles in primary human astrocytes and/or brain endothelial cells hCMEC/D3 in 3D collagen gels.

(a) Astrocyte culture 8 hours after application of glucose-coated gold nanoparticles to the gel surface. Nanoparticles are visible both in the gel matrix and the astrocytes (arrows). (b) Co-culture of astrocytes and hCMEC/D3 cells 8 hours after application of glucose-coated gold nanoparticles to the endothelial surface. Nanoparticles are detected both in the endothelium and the astrocyte (arrows). Small tears in the gel matrix are sometimes produced during the sectioning due to the presence of silver-enhanced gold nanoparticles. Scale bars = 500 nm.