Fabrication of an align-random distinct, heterogeneous nanofiber mat endowed with bifunctional properties for engineered 3D cardiac anisotropy

Abstract

The development of multilayered anisotropic scaffolds with a 3D anisotropy similar to that of native cardiac tissue with layer-specific oriented multiple cell layers is a major challenge in the reconstruction of engineered cardiac tissue in vitro. Herein, we present an electrospun align-random distinct, heterogeneous nanofiber (NF) mat to facilitate the construction of a multilayered anisotropic scaffold with different orientations, which recreates the cardiac anisotropy via hollow patterned electrolyte-assisted electrospinning (HP-ELES). Based on the HP-ELES process, a distinct but heterogeneous polycaprolactone (PCL) NF mat, which comprised an ultra-thin (<10 mu m) aligned NF membrane at the core and a thick random NF mat at the peripheral rim, was readily fabricated. The fabricated heterogeneous NF mat was endowed with bifunctional properties of not only uniaxially aligned topographical cues to align the cardiomyocytes (CMs) followed by creating a uniaxial contractile motion but also mechanical stability to enable manual manipulation provided by the aligned NF membrane and random NF mat, respectively. Intriguingly, the in vitro cell culture of CMs possessing spontaneous contraction on the heterogeneous NF mat demonstrated cell alignment and subsequent uniaxial contraction along with aligned NFs. The stacking triple layers also exhibited multiaxial contraction, which potentially simulates the squeezing force of the heart tissue. HP-ELES is highly expected to increase the use of ultra-thin aligned NF membranes for the development of in vitro anisotropic organ models and for in vivo tissue regeneration requiring multilayered anisotropic scaffolds owing to the ease of the manual manipulation of the membrane.