Guided three-dimensional growth of functional cardiomyocytes on polyethylene glycol nanostructures

We introduce well-defined nanopillar arrays of a poly(ethylene glycol) (PEG) hydrogel as a cell culture platform to guide a 3D construct of primary rat cardiomyocytes in vitro for potential tissue engineering applications. Ultraviolet (UV)-assisted capillary lithography was used to fabricate highly uniform ∼150 nm PEG pillars with ∼400 nm height. It was found that cell adhesion was significantly enhanced on PEG nanopillars (132 ± 29 cells/mm ²) compared to that on the bare PEG control (39 ± 17 cells/mm ²) (p < 0.05) but substantially reduced compared to that on the glass control (502 ± 45 cells/mm2) (p < 0.01). Furthermore, in colonizing cardiomyocytes, the nanopillars stimulated self-assembled aggregates among the contacting cells with 3D growth, which is a unique feature for nanopatterned PEG hydrogels as a cell culture substrate. The 3D-grown cardiomyocytes retained their conductive and contractile properties, as evidenced by the observation of beating cardiomyocytes with robust action potential generation.