Average RGD densities per surface area and RGD spacing for various RGD∶OMe ratios.

RGD stands for surfaces modified with 100% EO6-RGD. To calculate RGD densities, surface area per alkyl chain in the base monolayer of 0.255 nm2 and an overall yield of 15% for the bio-functionalisation of silicon with RGD was used. For 100% EO6-RGD this yields one RGD molecule per 1.7 nm2 surface area. For surfaces with varying ratios of EO6-RGD to EO6-OMe (RGD∶OMe ratio), the RGD density is calculated by taking the dilution ratio into account. For calculation of the RGD–to-RGD spacing, it was assumed that the RGD molecules are arranged in a hexagonal pattern.