**6. Conclusion**

To evaluate IGF-1 pathway, Akt is the most important protein that regulates skeletal muscle differentiation and hypertrophy. It was also reported that IGF-1 dependent Akt-phosphoralization increased along with higher rate of myogenic differentiation. Properties of MyoD, responsible for skeletal muscle differentiation, are controlled by Akt and blockage of Akt prevents formation of skeletal muscle transcriptosome [24–26]. The present investigation demonstrates that the investigated pathway proteins expressed better on GO-PCL composite meshes than those on GO sheet or control (tissue culture plate). Up-regulation of such pathway proteins on GO-PCL further emphasize the IGF-1 pathway which is related to skeletal muscle development. Thus, it reveals the importance GO-PCL composite meshes for skeletal muscle

242 Umbilical Cord Blood Banking for Clinical Application and Regenerative Medicine

**Figure 27.** Expression of PI(3)k, Akt, pAkt, IRS-1 (a) and expression of fold change for these corresponding signalling proteins (b) on control (tissue culture plate), GO sheet and GO-PCL meshes. \* indicates significant difference (*p* < 0.05).

As mentioned above, Akt is a major component that regulates IGF-1 pathway. Inhibition of Akt deters IGF-I-stimulated nuclear translocation of Akt and also suppresses the growth of various cells. Akt is a vital component of the cell survival pathway as it functions by resisting apoptosis via improving communication between cells that are damaged [26, 27]. Inhibition of Akt results in much higher rate of apoptosis and a decrease in IGF-1 cell signalling. Inhibition of Akt was done using 10-DEBC hydrochloride, a selective and precise cell permeable Akt phosphorylation inhibitor that shows no activity at PDK1, SGK1 or PI 3-kinase [27, 28]. In the present experiment, the expression of MyoD, a vital myogenic protein that helps in myogenic differentiation has been studied by pre- and post-Akt inhibition. The results showed (**Figure 28**) that after inhibition of Akt, the expression of MyoD intensity decreased rapidly. Akt inhibitor inhibits IGF-I-stimulated nuclear translocation of Akt that results in much reduction

tissue engineering applications.

*5.3.3. Effect of Akt inhibition on MyoD expression*

ElectrospunGOnPs-PCL and GOnPs-PLGA composite scaffolds showed enhanced conductivity and dielectric permittivity due to quantum tunnelling between the graphene oxide nanoflakes. Improved conductivity of the scaffold enhanced biocompatibility of the GOnPspolymer composite fibrous meshes compared to those of pure polymers like PCL and PLGA. As a consequence, the composite scaffolds showed excellent myoblast differentiation of umbilical cord blood derived mesenchymal stem cells. Increased biocompatibility of GO and GO-polymer composites were attributed to the surface charge and nanoflake structure of graphene oxide. Compared to GOnPs-PLGA, GonPs-PCL composite scaffold meshes exhibited better myoblast differentiation capability which is attributed to the more conducting behaviour of the GOnPs-PCL composite. IGF-1 cell signalling pathway study carried out on the composite scaffold meshes also showed potentiality for excellent myoblast differentiation and proliferation of cord blood stem cells (CB-hMSCs).Therefore, in demand of cell specific substrates, the use of GO-based polymer composite meshes might be considered as the most potential substrates for the next generation tissue engineering and other biomedical applications. Moreover, it is also worthwhile to mention that cost effective and easily available umbilical cord blood is an important and abundant source of human stem cells for the differentiation of skeletal muscle tissues or other lineages.
