Electrohydrodynamic\nPrinting of Microscale Fibrous\nScaffolds with a Sinusoidal Structure for Enhancing the Contractility\nof Cardiomyocytes

Mimicking the curved collagenous fibers in the cardiac\nextracellular\nmatrix to fabricate elastic scaffolds <i>in vitro</i> is\nimportant for cardiac tissue engineering. Here, we developed sinusoidal\npolycaprolactone (PCL) fibrous scaffolds with commendable flexibility\nand elasticity to enhance the contractility of primary cardiomyocytes\nby employing melt-based electrohydrodynamic (EHD) printing. Microscale\nsinusoidal PCL fibers with an average diameter of ∼10 μm\nwere printed to mimic the collagenous fibers in the cardiac ECM. The\nsinusoidal PCL fibrous scaffolds were EHD-printed in a layer-by-layer\nmanner and exhibited outstanding flexibility and elasticity compared\nwith the straight ones. The sinusoidal PCL scaffolds provided an elastic\nmicroenvironment for the attaching and spreading of primary cardiomyocytes,\nwhich facilitated their synchronous contractive activities. Primary\ncardiomyocytes also showed improved gene expression and maturation\non the sinusoidal PCL scaffolds under electrical stimulation for 5\ndays. It is envisioned that the proposed flexible fibrous scaffold\nwith biomimetic architecture may serve as a suitable patch for tissue\nregeneration and repair of damaged hearts after myocardial infarction.