(Fig.4.3f). All animal procedures conformed to US National Institutes of Health
guidelines and were approved by Harvard University’s Animal Care and Use
Committee.
Vascular construct: Synthetic vascular constructs were produced in a manner
similar to the sheet-based tissue engineering approach described previously [ 31 ]
(Fig.4.4). First, the mesh nanoES were coated with gelatin/fibronectin solution
overnight (Fig.4.4a–c). Second, human aortic smooth muscle cells were seeded at a
density of 1 104 cm−^2 on the gelatin/fibronectin-coated devices and cultured in
Medium 231 supplemented with smooth muscle growth supplement (Fig.4.4d).
Sodium L-ascorbate was added to the culture medium to stimulate extracellular
matrix (ECM) synthesis as previous report [ 31 ]. Human aortic smooth muscle cells
(HASMCs) were maintained in incubator until their secreted ECM proteins formed
a cohesive tissue sheet [ 31 ] that can be easily peeled off from the silicon substrate.
Fig. 4.3 Schematic of cardiomyocyte 3D culture.aA free-standing mesh-like nanoES.bHybrid
of PLGA electrospunfibers and mesh-like nanoES.cIndividual devices were wire-bonded to PCB
connecters.dA culture chamber wasfixed over the scaffold.eThe hybrid scaffold was seeded
with cardiomyocytes/Matrigel.fThe cardiac sheet (e) was folded and cultivated for an additional
3 – 10 days.gA mesh device showing the free-standing part (the right half) and thefixed part on
the wafer (the left half). The arrow marks the outer-electrode pins for wire-bonding.hPrinted
circuit board (PCB) with wire-bonding wires. The wires connected the PCB copper pads (left) and
the rectangular electrodes on the supported end of the mesh-like nanoES (right). White dots
highlight bonding points. Arrows highlight one wire-bonded aluminum wire
44 4 Three-Dimensional Macroporous Nanoelectronics...