Development of tissue-engineered skeletal muscle manufacturing variables

Three-dimensional tissue-engineered structures enable more representative determination of novel drug or material effects on tissue than traditional monolayer cell cultures. This study sought to better understand how key manufacturing variables affect the myotube characteristics of a skeletal muscle model toward reducing resource use and to develop an understanding of scaling on model consistency. C2C12 murine myoblasts were seeded in a tethered collagen scaffold from which directional myotubes form in response to lines of tension and a change in medium. Collagen polymerizing area length-to-width ratios greater than one were found to reduced cell-matrix attachment and remodeling forces significantly (p < .05) correlating to a reduction in cell fusion potential. Following this, utilizing a factorial design of experiment, 4 million C2C12s/ml, with a polymerizing area width 150% of the anchor point, produced the most favorable myotube characteristics and dramatically reduced the incidence of rupture. Scaled constructs showed no significant differences when compared to larger models. Approximately 20 myotubes with a variation in the alignment of <25 degrees in the central region were consistently observed in the final models. This demonstrates the influence of initial manufacturing variables on tissue formation and has produced a benchmark model for consistent production across scaled constructs for future optimization and as a potential cost-effective preclinical testbed.