High Throughput Techniques for the Investigation of Cell–Material Interactions - Biointerfaces: Where Material Meets Biology - page 294

d n 3 r 4 n g | 7

.

Figure 10.16 Examples of several RGD gradients: (A) schematic of the microfluidics
device used to create hydrogel gradients; (B) schematic for the prepar-
ation of (i) hydrolysed PMMA gradients, (ii) subsequent biotin-strep-
tavidin-biotin-PEG-RGD binding; (C) investigation of dendritic cell
response to RGD density gradients (gradient fabrication method de-
scribed in Figure 10.10), stained for CD86 (activation marker, green)
and cell nuclei (blue), demonstrating an increase in CD86 activation
with increasing RGD concentration.
Figures A, B and C adapted from Burdick et al., 222 Lagunas et al. 224,225
and Acharya et al., 76 respectively.

controlled hydrolysis via gradual immersion into a sodium hydroxide solu-
tion. Biotin was then immobilised on the reactive COOH groups followed by
subsequent coupling with RGD functionalised streptavidin. 224
Gallant et al. 173 demonstrated that in the presence of a surface-bound
RGD concentration gradient, the attachment of smooth muscle cells in-
creased with increasing RGD concentration (Figure 10.16C). As an extension
to this study, the up-regulated expression of activation markers and pro-
duction of cytokines in dendritic cells was shown to correlate with increasing