High Throughput Techniques for the Investigation of Cell–Material Interactions - Biointerfaces: Where Material Meets Biology - page 277

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.

Figure 10.9 Schematic showing the methods used to create nanoparticle density

gradients: (A) plasma polymer chemical template with subsequent
nanoparticle attachment; 51 (B) electrostatic attachment of nanoparti-
cles, 146 (i) schematic for gradient formation, (ii) osteoblast cell response
to nanoparticle gradient, (iii) graph demonstrating that as the density
of the nanoparticles decreases the cell density increases; (C) polymer
brush chemical gradient template for nanoparticle gradient format-
ion, 144 through adjusting the (i) polymer chain length, (ii) grafting
density; (D) AFM images of nanoparticle gradient prepared through
using an APTES silane gradient template. 145

generate a gold nanoparticle gradient (Figure 10.9A). Gold nanoparticle ad-
hesion correlated well with the amine functional groups in the allylamine-
octadiene chemical gradient. Bhat et al. 112,145 used an organosilane vapour
deposition technique to form a concentration gradient of aminopropyl-
triethoxysilane (APTES) on flat silicon substrates (Figure 10.9D). 89 The
negatively charged gold nanoparticles were then electrostatically attracted to
the positively charged APTES, resulting in the binding of particles to the
regions covered by APTES. 112 Nanoparticles can also adsorbed onto grafted