ARTICLES NATURE MATERIALS DOl: 10.1038/NMAT3404 Lumen Lumen Inner tubing PDMS Vascular construct Inner 1000 Time(s) Figure 6 Synthetic vascular construct enabled for sensing a, Schematic of the synthesis of smooth muscle nanoES. The upper panels are side views, and he lower ones are either top views (I and ii) or a zoom-in view (lll). Grey: mesh nano ES: blue fibres: collagenous matrix secreted by HASMcs; yellow dots nanowire FETs: pink: HASMCs. b, (I) Photograph of a single HASMC sheet cultured with sodium L-ascorbate on a nanoES (iI) Zoomed-in view of the dashed area in L, showing metallic interconnects macroscopically integrated with cellular sheet. Scale bar, 5 mm. c, Photograph of the vascular construct after rolling into a tube and maturation in a culture chamber for three weeks. Scale bar, 5 mm. d (i) Micro-computed tomograph of a tubular construct segment. (ID)Zoomed-in view of the area outlined in I. The arrows mark the individual nanowire FET-containing layers of the rolled construct. Scale bar, 1mm. e, Haematoxylin-Eosin-(I) and Masson-Trichrome-(Il; collagen is blue)stained sections(-6 um thick) cut perpendicular to the tube axis; lumen regions are labelled. The arrows mark the positions of Su-8 ribbons of the nanoES Scale bars, 50um f, Changes in conductance over time for two nanowire Fet devices located in the outermost (red) and innermost (blue) layers. The inset shows a schematic of the experimental set-up. Outer tubing delivered bathing solutions with varying pH (red dashed lines and arrows); inner tubing delivered solutions with fixed pH (blue dashed lines and arrows) 992 NATURE MATERIALS I VOL 11 I NOVEMBER 2012 I G 2012 Macmillan Publishers Limited All rights reservedARTICLES NATURE MATERIALS DOI:10.1038/NMAT3404 a b d f e c I II I II II 0 500 1,000 1,500 2,000 2,500 7.6 7.5 7.4 7.3 7.2 7.1 7.0 6.9 6.8 6.7 6.6 6.5 6.4 6.3 200 nS Outer Ag/AgCl tubing Inner tubing PDMS I II III Lumen Outer Inner Time (s) Conductance Lumen Lumen I Vascular construct Figure 6 | Synthetic vascular construct enabled for sensing. a, Schematic of the synthesis of smooth muscle nanoES. The upper panels are side views, and the lower ones are either top views (I and II) or a zoom-in view (III). Grey: mesh nanoES; blue fibres: collagenous matrix secreted by HASMCs; yellow dots: nanowire FETs; pink: HASMCs. b, (I) Photograph of a single HASMC sheet cultured with sodium L-ascorbate on a nanoES. (II) Zoomed-in view of the dashed area in I, showing metallic interconnects macroscopically integrated with cellular sheet. Scale bar, 5 mm. c, Photograph of the vascular construct after rolling into a tube and maturation in a culture chamber for three weeks. Scale bar, 5 mm. d (I) Micro-computed tomograph of a tubular construct segment. (II) Zoomed-in view of the area outlined in I. The arrows mark the individual nanowire FET-containing layers of the rolled construct. Scale bar, 1 mm. e, Haematoxylin–Eosin- (I) and Masson-Trichrome- (II; collagen is blue) stained sections (∼6 µm thick) cut perpendicular to the tube axis; lumen regions are labelled. The arrows mark the positions of SU-8 ribbons of the nanoES. Scale bars, 50 µm. f, Changes in conductance over time for two nanowire FET devices located in the outermost (red) and innermost (blue) layers. The inset shows a schematic of the experimental set-up. Outer tubing delivered bathing solutions with varying pH (red dashed lines and arrows); inner tubing delivered solutions with fixed pH (blue dashed lines and arrows). 992 NATURE MATERIALS | VOL 11 | NOVEMBER 2012 | www.nature.com/naturematerials © 2012 Macmillan Publishers Limited. All rights reserved