Figure 14 represents the results obtained from MTT assay. In this figure, it can be observed that all the nanofiber combinations show the logarithmic check details phase of growth as the days of incubation pass (i.e., 1, 2, and 3 days). Moreover, the cell viability of see more nanofibers modified with HAp showed an increase in the growth as the concentration of HAp is increased. These results further suggest that used HAp NPs are non-toxic to cells, and there is a considerable positive impact induced by HAp NPs. Figure 14 MTT assay results revealing cell viability after culturing the NIH 3 T3 fibroblasts

in the presence of nanofibers. To find out the cell attachment on nanofibers, the results after culturing the fibroblast for 3 and 12 days is presented in Figures 15 and 16. In case of culturing the cells for 3 days, it can be seen that the cells are properly attaching on nanofiber surfaces. After looking on the cells, it is highly realized that the cells are stress-free and are growing in a healthy manner. Furthermore, the cell attachment results after culturing the cells for 12 days are presented in Figure 15. In this figure, we can see the confluent growth of cells on nanofiber surfaces which further indicates the non-toxic nature of nanocomposites. However, from these figures (i.e., Figures 15 and 16), it can be observed that cell attachment is independent

to the presence of HAp in nanofibers. Figure 15 Results

YM155 of the cell attachment after culturing the NIH 3 T3 fibroblasts in the presence of nanofibers for 3 days. For pristine silk fibroin nanofibers (A), silk fibroin nanofibers modified with 10% HAp (B), 30% HAp (C), and 50% HAp (D). Figure 16 Results of the cell attachment after culturing the NIH 3 T3 fibroblasts in the presence of nanofibers for 12 days. For pristine silk fibroin nanofibers (A), silk fibroin nanofibers modified with 10% HAp (B), 30% HAp (C), and 50% HAp (D). much Conclusions In conclusion, a highly trustable technique which employs the use of stopcock connector can be used to electrospun a blend solution of fibroin and HAp together in aqueous solutions, which is impossible if simple mixing procedure is followed. Without the use of any toxic chemical, this technique can yield nanofibers with desirable properties. The FE-SEM and TEM techniques can be used to figure out the location of HAp in nanofibers and simultaneously support the use of stopcock connector to electrospun silk fibroin and HAp NPs. Fourier transform infrared spectroscopy analysis indicated the chemical interaction occurring between HAp NPs and silk fibroin, which resulted in the transformation of random coil to β-sheet confirmation of silk fibroin. It can also be concluded that HAp NPs enhanced the β-sheet conformation of fibroin and resulted in the improvement of the properties of nanofibers.