Reactive keratin derivatives: A promising strategy for covalent binding to hair

Improvement of the adhesion of conductive poly(m-toluidine) onto chemically reduced-wool fabrics

“…After the reduction of wool keratin with NaHS, the bands corresponding to the defined peptide bonds also detected with the slight shifts to the lower wavenumbers. This observation may suggest that the protein structure of the wool was not significantly affected by the NaHS reduction process, as similarly observed with the literature [15]. When the shifts occurred in the bands of amide-I are considered, it can be said that the secondary structure of the wool proteins may have been changed because in the studies reporting the extraction of the wool keratin [10,27] the changes in the position of the amide I band in the FTIR spectra were attributed to a change from α -helix (ca~1650 cm −1 ) to β -sheet structure (ca.~1630 cm −1 ) .…”

“…The ATR-FTIR spectra of the samples are comparatively presented in Figure 5. As seen from the wool spectrum, the bands located around 3275, 1640, and 1534 cm −1 are attributed to the stretching vibrations of peptide bonds, including N-H, C =O (amide-I), and bending vibration of N-H (amide-II) [12,15]. The other bands at 1396 and 1074 cm −1 are also assigned to the stretching vibrations of the axial deformation of C =O and S-O groups, respectively [1].…”

“…Among them, thanks to providing irreversible disulphide cleavage of keratin with high reaction yields [10], chemical reduction methods are found promising by the researchers. In the method, the disulphide link of keratin can be converted into oxidized another disulphide form (reconstruction) [10,13] or disrupted to give SH groups, through chemical reducing agents that are capable of attacking disulphide links containing S atoms such as mercaptoethanol, L-cysteine, thioglycolic acid (TGA), and sodium hydrosulphide hydrate (NaHS.xH 2 O) under controlled pH in the presence or absence of urea [8][9][10][11]14,15]. In this work, we preferred the use of TGA and NaHS as organic and inorganic reducing agents for the cleavage of disulphides, respectively.…”

Drug‐Conjugation Induced Self‐Assembly of Feather Keratin‐Based Prodrug for Tumor Intracellular Reduction Triggered Drug Delivery

“…In the FT-IR spectra (Figure 2b), a strong absorbance of the stretching vibrations of C-O-C in PEG at 1100 cm −1 could be seen in PK and its derivatives PK-SS-COOH and PK-SS-D, [18] indicating the successful PEGylation of keratin. After coupling with MPA, the broad characteristic absorbance of the SH groups in keratin at about 2100 cm −1 dissapeared, [19] while another characteristic absorbance of the SS bond emerged at 580 cm −1 , [20] revealing the successful oxidative coupling of PK with MPA. Furthermore, the characteristic absorbance of CO in DOX was found at 1724 cm −1 in the spectrum of the PK-SS-D, [21] demonstrating the successful synthesis.…”

Preparation and Characterization of Biomimetic Hydroxyapatite Nanocrystals by Using Partially Hydrolyzed Keratin as Template Agent

“…As one type of protein, keratins widely exist in biological systems, comprising the main component of natural materials such as hair, fur, wool, nails, hooves, and fish scales [9,10,11,12,13,14]. The helical molecular structure and macromolecular organization of α-keratin impart these materials with notable characteristics such as strength and flexibility [15].…”