Aligned fibrous scaffolds for enhanced mechanoresponse and tenogenesis of mesenchymal stem cells

Topographical cell guidance has been utilized as a tissue-engineering technique to produce aligned cellular orientation in the regeneration of tendon- and ligament-like tissues. Other studies have investigated the effects of dynamic culture to achieve the same end. These works have, however, been limited to two-dimensional cultures, with focus given to the effects from the stimuli independently. The understanding of their combined effects in the tenogenic differentiation of mesenchymal stem cells (MSCs) has also been lacking. This study investigated the synergistic effects of mechanical stimulation on aligned MSCs in a three-dimensional (3D) aligned silk fibroin (SF) hybrid scaffold. Enhanced tenogenesis of seeded MSCs was observed in the scaffold group with aligned SF electrospun fibers (AL) under static culture conditions, as evidenced by the upregulation in expression and production of tendon/ligament-related proteins. The intensity and onset of these differentiative markers were increased and advanced, respectively, under dynamic culture conditions, indicative of an accelerated matrix deposition and remodeling process. Consequently, the tensile properties of dynamically cultured AL were significantly improved. We thus propose that the aligned hybrid SF scaffold facilitates mechanoactivity and tenogenic differentiation of MSCs by intensifying the positive effects of mechanical stimulation in a 3D environment.