Figure 10. F-actin fluorescence staining in C2C12 cells cultivated for 7 days on cellulose acetate (A) and cellulose acetate nanofiber with annatto extract (B). Cell nuclei and F-actin were stained with DAPI (blue) and phalloidin (orange), respectively. Scale bar: 500 µm.
To do so, cells were cultivated on the nanofibers for 7 days, since the actin cytoskeleton in this system is more easily resolved in higher density samples. C2C12 myoblasts can be found in a wide range of morphologies in vitro and progressively change shape during the fusion/differentiation process to become elongated and fusiform [47]. We found that the cells cultivated onto the CA nanofibers were aligned and elongated (Figure 10A), suggesting that they were beginning the differentiation process. The cells cultivated onto the CA@A nanofibers were thinner and elongated (Figure 10B), with random orientation of the actin cytoskeleton. This indicates that the shape of the cells growing in the CA nanofiber may be related to greater capacity for cell differentiation in this matrix, whereas myoblasts in the CA@A nanofibers may have a greater chance of proliferating before the differentiation process begins.