Efficient Myogenic Activities Achieved through Blade-Casting-Assisted Bioprinting of Aligned Myoblasts Laden in Collagen Bioink.

This study investigated mechanical stimulation combined with three-dimensional (3D) bioprinting as a new approach for introducing biophysical and biological cues for tissue regeneration. A blade-casting method in conjunction with bioprinting was employed to fabricate bioengineered skeletal muscle constructs using a bioink composed of C2C12 myoblasts and collagen type-I. Various printing process parameters were selected and optimized to achieve a highly organized cell alignment within the constructs. The resulting cell-aligned constructs demonstrated remarkable improvement in actin filament alignment and cell proliferation compared with conventionally printed cell-laden constructs. This improvement can be attributed to the synergistic effects of mechanotransduction, facilitating the cellular response to mechanical cues and the alignment of fibrillated collagen, which plays a significant role in modulating cellular functions and promoting muscle tissue regeneration. Furthermore, we assessed the impact of blade casting combined with 3D bioprinting on gene expression. The expression levels of myogenesis-related genes were substantially upregulated, with an approximately 1.6-fold increase compared to the constructs fabricated without the blade-casting technique. The results demonstrated the effectiveness of combining mechanical stimulation through blade casting with 3D bioprinting in promoting aligned cell structures, enhancing cellular functions, and driving muscle tissue regeneration.