Figure 5.

SAM patterning using backfilling. ^[42] A) Schematic representation of one type of backfilling patterning approach: 1) Adhere elastomeric stencil to gold substrate to generate a microwell array superstructure, 2) locally form a SAM in each well with alkanethiolate mixtures containing carboxylic acid-terminated and hydroxyl-terminated OEG-alkanethiolates, 3) covalently conjugate peptides to array spots by carbodiimide condensation of peptide N-terminal primary amine and SAM carboxylic acid terminal moities, and 4) remove mask and backfill remaining bare gold areas with an inert alkanethiolate such as HS–C₁₁–EG₃–OH. SAMs patterned with GRGDSP using this backfilling approach have been used to culture a range of human cell types including B) umbilical vein endothelial cells, C) mesenchymal stem cells, D) dermal fibroblasts, E) fibrosarcoma cells (HT-1080s), and F) embryonic stem cells. Furthermore, we have demonstrated that hMSCs seeded on SAM arrays at G) 50000 cellscm ⁻² remain confined to the patterned spot over H) 20 days.