captured with an accelerating voltage of 3 KV with magnifications of 1 K. Preparation of aqueous regenerated silk solutions The aqueous silk solutions to be used for electrospinning were prepared by the following procedure. Firstly, degumming was achieved by cutting Bombyx mori cocoons into suitable pieces and were boiled in 0.02 M Na2CO3 for an hour and subsequently washed with de-ionized water (2 to 3 times) to remove the unbound sericin. Later on, the samples were dried at room temperature for 1 day. After drying, 60 g of degummed silk was dissolved in ternary solvent composed of CaCl2/Ethanol/H2O (32/26/42, wt/wt/wt) at 98°C for 40 min in round-bottomed flasks. Following this, protein mixture was filtered through miracloth (Calbiochem, San Diego,
CA, USA) to remove small aggregates. Furthermore, this solution was dialyzed against deionized water using a dialysis tubing with molecular weight cutoff 12,000 to 14,000 Da (Spectra/Por®, Rancho Dominguez, Enzalutamide in vivo CA, USA) for 3 days, and water was exchanged once a day. The yielding aqueous silk fibroin solution was calculated to be 8 wt.% (which was determined by weighing the remaining solid weight after drying). Finally, the aqueous silk fibroin solutions were stored in a refrigerator and used within 15 days of time to avoid denaturation and/or precipitation. Nature of used HAp NPs Before using the HAp NPs for modifying the nanofibers, the NPs were characterized for shape and size. In this regard, the morphology of obtained HAp NPs was checked by TEM. Figure 1 provides the information about the morphological feature of HAp NPs. From these results, it can be seen that HAp NPs are rod-shaped and are having lengths of 100 to 110 nm
and diameters of 20 to 30 nm. These morphology and size provide initial confirmation that they are of appropriate shape and size to fit inside the nanofibers. Figure 1 Transmission electron micrograph showing the morphology of used HAp NPs. Polymeric solution preparation for electrospinning For preparing solution to electrospun Baricitinib pristine silk nanofibers, 20 ml of 8 wt.% of aqueous silk solution was removed from the refrigerator. To give appropriate viscosity to this solution, so as to have proper bending instability for fiber formation, 4 ml of previously prepared 30 wt.% PEO solution was added as a ‘sacrificial polymer.’ The resultant blend solutions were loaded in syringes and used for electrospinning. For preparing solutions to fabricate silk fibroin nanofibers containing HAp NPs, a stepwise methodology was adopted. On one hand, silk solution was prepared in the same way as mentioned for the preparation of pristine silk nanofibers and subsequently loaded in syringes. On the other hand, PEO/HAp colloidal solution was prepared by adding 2 g of PEO in 20 ml of 0.