Three-Dimensional Microfibrous Bundle Structure Fabricated Using an Electric Field-Assisted/Cell Printing Process for Muscle Tissue Regeneration.

In tissue engineering, biomimetic scaffolds are developed to provide cells with a microenvironment that promotes cellular activities. In this study, we present a three-dimensional (3D) fibrous bundle structure fabricated using an electrohydrodynamic process and a cell printing process using myoblast-laden collagen bioink. An anisotropic topographical cue in a 3D structure is an important factor for muscle tissue regeneration, and therefore, the fibrous bundle structure was uniaxially stretched using optimized conditions for fiber alignment. In addition, for stable cell attachment to facilitate the effect of topological cues, the myoblasts were efficiently released from the collagen bioink. We observed that the 3D fibrous bundle structure was an effective in vitro platform that induced cell proliferation and the formation of myotubes. The synergistic combination of the aligned topological cues and high biocompatibility of collagen enhanced the formation of myotubes, which was represented by the relative expression of myogenic genes (Myf5, Myh2, MyoD, and Myogenin). Therefore, we could confirm the feasibility of the 3D fibrous bundle structure for the regeneration of skeletal muscle tissues.