Hierarchical Topography with Tunable Micro- and Nanoarchitectonics for Highly Enhanced Cardiomyocyte Maturation Via Multi-Scale Mechanotransduction.

Enhancing cardiomyocyte (CM) maturation by topographical cues is a critical issue in cardiac tissue engineering. Thus far, single-scale topographies with a broad range of feature shapes and dimensions have been utilized including grooves, pillars and fibers. This study reports for the first time a hierarchical structure composed of nano-pillars (nPs) on micro-wrinkles (μWs) for effective maturation of CMs. Through capillary force lithography followed by a wrinkling process, vast size ranges of topographies were fabricated, and the responses of CMs were systematically investigated. Maturation of CMs on our hierarchical structures was highly enhanced compared to a single-scale topography: cardiac differentiation of H9C2s (rat cardiomyocytes) on the hierarchical topography was ∼ 2.8 and ∼ 1.9 times higher than those consisting of single-scale μWs and nPs. Both nPs and μWs have important roles in cardiac maturation, and the aspect ratio (height/diameter) of the nPs and the wavelength of the μWs are important in CM maturation. This enhancement was caused by strong focal adhesion and nucleus mediated mechanotransduction of CMs from the confinement effects of the different wavelengths of μWs and the cellular membrane protrusion on the nPs. This study demonstrates how a large family of hierarchical structures are used for cardiac maturation. This article is protected by copyright. All rights reserved.