In the human body, there are numerous microtubular tissue structures, such as muscles, vessels, nerves, and tendons. Tissue engineering scaffolds have been regarded as a high-potential candidate for providing such aligned instructive niches to facilitate cell-recruitment and differentiation, and eventually, successful tissue regeneration. Moreover, scaffolds derived from the extracellular matrix (ECM) can provide excellent biocompatibility. However, the fabrication of such microtubular hierarchical scaffolds using ECM has proven to be difficult, and thus, innovative fabrication approaches are required. Herein, we have developed a biofabrication system involving a sequential removal of supporting materials (polycaprolactone (PCL) and poly(vinyl alcohol) (PVA)) to fabricate a uniaxially aligned microtubular collagen scaffold, a lotus-like structure. To generate the unique morphological structures of the scaffold, we manipulated various material-related and processing factors, such as the molecular weight of PVA and the weight fraction of collagen coating. Physical and biological activities of the aligned hierarchical microtubular collagen scaffolds were compared with those of the controls (conventional collagen struts and microtubular collagen scaffolds void of a uniaxial topographical cue). In conclusion, the instructive niche on the aligned hierarchical microtubular collagen structure induced high degrees of myoblast alignment and efficient myogenic differentiation.
Keywords: 3D printing; biomimetic; collagen; lotus-root-like scaffold; skeletal muscle.