File Name : esi_fig1_23dec2013.tif

Caption : esi fig. 1 bilayer plasma stencilling technique1: a flexible pdms membrane with through-holes connected on the basal side by micron-scale channels (left). plasma stencilling a pll-g-peg-coated substrate replicates the pattern for localised protein deposition (conjugated with fitc, top right). neuron-like differentiated human sh-sy5y neuron-like cells adhere to the nodes and extend outgrowths to form an interconnected neuronal network (bottom right). modified and reproduced with permission of the royal society of chemistry.

File Name : esi_fig2_polylysineonpllgpeg.tif

Caption : esi fig. 2 the addition of pll-fitc to a plasma patterned surface coated with pll-g-peg. the pegylated surface does not prevent the adsorption of pl.

File Name : esi_fig3_tcs_peg.tif

Caption : esi fig. 3 tcs-peg/pll-fitc patterns. immediately after back filling with pll-fitc, patterning was observed. however, these patterns were not reproducibly transferred across the entire surface and were of low stability, rapidly decaying while stored in buffers or cell media.

File Name : esi_fig4_mediaeffects.tif

Caption : esi fig. 4 pll-fitc patterns fabricated using surplus bilayer stencils were imaged immediately after preparation (control) and following incubation for 30 minutes or 18 hours in different culture media. the dmem cell culture media has minimal effect on pattern integrity, whereas in the presence of essential growth supplements (10% (v/v) fcs or lipumin) the pattern decays noticeably in 30 minutes, with significant non-specific adsorption following overnight incubation (18 h).

File Name : esi_fig5__dcdms_pll_cn.tif

Caption : esi fig. 5 a dcdms/pll-fitc pattern imaged immediately after preparation (top) and choice results of rare patterns of cortical neurons following 5 div culture (bottom).

File Name : esi_fig6_stability.tif

Caption : esi fig. 6 cortical neurons adhering to a dcdms-aminosilane pattern following 5 div culture. 

File Name : esi_fig7_largeareapatterns.tif

Caption : esi fig. 7 large area pattern compliance (156 nodes) of cortical neurons on pll-g-peg-coated substrates patterned with pl by microcontact printing. the spatial organisation of the neuronal networks was stable for 33 div (the experiment was concluded at this time point). 

File Name : esi_fig8_redefinecpnbyoccupancy.tif

Caption : esi fig. 8 redefining the occupancy and connections per node (cpn) terms. clustering reduces node occupancy and consequently the cpn level (black). expanding the node occupancy term to further include occupancy by neurite outgrowth results in maintained occupancy and cpn levels (red). 

File Name : esi_fig9_stability.tif

Caption : esi fig. 9 pll-g-peg stability. zeta potential measurements demonstrate that the stability of peg coatings decay significantly within 2 months when stored in air. in contrast, storage in a n2 atmosphere (with oxygen displaced) prolongs the stability of the adlayer, with only a minor (~15 mv) drop in the zeta potential during storage for over a year. similar preservation can be achieved by storing the substrates in argon at -80 °c.