Mechanical Stimulation and Aligned Poly(ε-caprolactone)-Gelatin Electrospun Scaffolds Promote Skeletal Muscle Regeneration.

The current treatments to restore skeletal muscle defects present several injuries. The creation of scaffolds and implant that allow the regeneration of this tissue is a solution that is reaching the researchers' interest. To achieve this, electrospinning is a useful technique to manufacture scaffolds with nanofibers with different orientation. In this work, polycaprolactone and gelatin solutions were tested to fabricate electrospun scaffolds with two degrees of alignment between their fibers: random and aligned. These scaffolds can be seeded with myoblast C2C12 and then stimulated with a mechanical bioreactor that mimics the physiological conditions of the tissue. Cell viability as well as cytoskeletal morphology and functionality was measured. Myotubes in aligned scaffolds (9.84 ± 1.15 μm) were thinner than in random scaffolds (11.55 ± 3.39 μm; = 0.001). Mechanical stimulation increased the width of myotubes (12.92 ± 3.29 μm; < 0.001), nuclear fusion (95.73 ± 1.05%; = 0.004), and actin density (80.13 ± 13.52%; = 0.017) in aligned scaffolds regarding the control. Moreover, both scaffolds showed high myotube contractility, which was increased in mechanically stimulated aligned scaffolds. These scaffolds were also electrostimulated at different frequencies and they showed promising results. In general, mechanically stimulated aligned scaffolds allow the regeneration of skeletal muscle, increasing viability, fiber thickness, alignment, nuclear fusion, nuclear differentiation, and functionality.