In the spectrum of the PLGA/nHA-I (Figure 3(d)), all the abovementioned bands were present at their characteristic positions. However, the reduced intensities of the bands for amide and carboxylic functionalities might be attributed to

the influence of the excess amount of PLGA used. Ku-0059436 nmr Figure 3 FTIR spectra of (a) pristine nHA, (b) nHA-I, (c) pristine PLGA, and (d) PLGA/nHA-I. X-ray photoelectron spectroscopy analysis The successful grafting of insulin on nHA using succinic acid as a spacer was confirmed by X-ray spectroscopy (XPS) (ESCA). Figure 4 shows the data obtained from the qualitative analysis of pristine nHA, nHA-I, PLGA, and PLGA/nHA-I. The N1s and S2p photoelectron signals were the markers of choice for confirmation of insulin grafting on the surface of succinic acid-modified nHA-s and the presence of insulin-grafted nHA-I in the PLGA nanofibers. nHA showed three photoelectron signals (Figure 4(a)), corresponding to Ca2p (347.9 eV) and Fedratinib research buy O1s (binding energy 536.1 eV) along with P2p (binding energy, 133.2 eV). Whereas PLGA (Figure 4(c)) showed two photoelectron signals, representing C1s (binding energy, 284.6 eV) and O1s (binding energy, 536.1 eV). On the other hand, two new photoelectron signals were observed

for the PLGA/nHA-I composite (Figure 4(d)) and nHA-I (Figure 4(b)), namely, representing nitrogen (N1s, at binding energy 397.9 eV) and sulfur (S2p, binding energy 164.05 eV), respectively. This confirmed successful grafting of insulin on the surface of pristine nHA Figure 4(b), and the presence of insulin-grafted nHA-I in the PLGA composite nanofiber scaffold PLGA polymer (Figure 4(d)). Figure 4 XPS graph of (a) pristine isometheptene nHA, (b) nHA-I, (c) pristine PLGA nanofiber scaffold, and (d) PLGA/nHA-I nanofiber composite scaffolds. Table 1 shows that the atomic wt.% of nitrogen (N) and sulfur (S) was zero in pristine nHA and PLGA. However, when the surface of nHA was modified with succinic acid and subsequently on grafting with insulin, the atomic wt.% of calcium (Ca) and phosphorous (P) decreased, whereas those of carbon (C), nitrogen (N), and sulfur

(S) increased due to succinic acid and further grafting of insulin on the surface of nHA. This increase in atomic wt.% clearly indicated that succinic acid and insulin had been successfully grafted onto pristine nHA. Through the addition of nHA-I to PLGA, the atomic wt.% of calcium (Ca), phosphorous (P), nirtogen (N), and sulfur (S) decreased whereas the atomic wt.% of carbon (C) increased, confirming the presence of nHA-I in the PLGA nanofiber matrix. Table 1 Chemical composition of nanofiber scaffolds calculated from ESCA (XPS) survey scan spectra Substances Atomic weight (%) C 0 Ca N P S nHA 7.7 66.6 17.8   12.6   PLGA 64.61 35.39         nHA-I 47.77 30.90 11.51 6.75 5.2 0.76 PLGA/nHA-I 63.38 27.40 4.12 3.10 2.75 0.25 X-ray diffraction spectroscopy study Figure 5 depicts the X-ray diffraction spectroscopy (XRD) profile of pristine nHA and nHA-I.