Figure 1

Implementation of human neurovascular unit with immunity (hNVUI) to assess neurotoxic effects of Aluminum oxide nanoparticles (AlNPs). (a) Schematic diagram of hNVUI platform to study: (i) AlNP penetration across blood–brain barrier (BBB) and translocation to brain area and (ii) AlNP-driven neuroinflammation leading to neurodegeneration. L.C. represents a left-side chamber; R.C. represents a right-side chamber. (b) Experimental timeline for the AlNP-treated model preparation. (c) Effects of AlNPs on the diffusion of FITC-dextran passing through BBB. FITC-dextran (10 μM, M.W. 40 kDa, green) was added to the lumen side of L.C. and the diffusion of FITC-dextran toward R.C. was monitored for 24 h. (d) Assessment of permeability coefficient of 40 kDa FITC-dextran with or without AlNPs for BBB formed in L.C. (e) Fluorescent images of endothelial cells (ECs) after exposed to control media (Con) and 1 ng/mL of AlNPs in L.C. side, which were stained with VE-cad and Hoechst indicating EC’s tight-junctions and nucleus, respectively. (f–h) Quantitative results of (f) VE-cad expression, (g) EC contact area, and (h) EC size were measured from (e) and represented as bar graphs. (i) Fluorescent images of reactive astrocytes and neurons in R.C. side marked by GFAP and Tuj-1. (j–k) Quantitative results of (j) GFAP, and (k) Tuj-1 were measured from (i) represented as bar graphs. Scale bars, (c) 500 μm and (e, i) 100 μm. Inset scale bars, 20 μm. All data are presented as mean ± SD measured by two-tailed unpaired Student’s t-test. *, p < 0.05 and ****, p < 0.0001.