Hydrogels and Self-Assemled Nanostructures Based on Wool Keratose

• Main Author: Pakkaner, Efecan
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01-01-2017
• Subjects: Analytical chemistry; Animal sciences; Atomic physics; Biocompatibility; Biology; Biomedical engineering; Biomedical materials; Biopolymers; Cell culture; Cell growth; Cellular biology; Chemical bonds; Collagen; Cytotoxicity; Engineering; Fourier transforms; Hair; Heat resistance; Hydrogels; Mammals; Mathematics; Molecular weight; Morphology; Optics; Peptides; Physics; Polymer chemistry; Polymers; Proteins; Research methodology; Rheology; Scanning electron microscopy; Spectrum analysis; Tissue engineering; Wool; Wound healing
• ISBN: 9798505503225

In this study, water soluble keratose proteins were extracted from “Ovis aries” wool using peracetic acid oxidation with a yield of 35 ± 5 %. Wool samples and the extracted keratose proteins were characterized by using FT-IR, XRD, SEM and TGA techniques. α-keratose fractions (MW = 43-53 kDa) along with cleaved fragments of αkeratoses with molecular weights between 23 and 33 kDa were identified in the extracted protein mixture using SDS-PAGE analysis. DLS and AFM experiments indicated selfassembled globular nanoparticles with diameters of 20-40 nm formed at 5 and 10 mg/ml keratose concentrations. On the other hand, at 10 % w/v keratose concentration interconnected keratose hydrogels with pore sizes of 6 ± 4 and 7 ± 4 µm were obtained upon incubation at 37 and 50 °C, respectively. Storage moduli (G’) of these physical hydrogels were increased from ~100 to ~1000 Pa, as gelation temperature was increased from 37 to 50 °C. Hydrogels were also obtained at 7.5 % w/v keratose concentration by the addition of a crosslinker, THPC. Amine group:crosslinker ratio was used as 1:1, 1:2 and 1:4. As the amount of crosslinker increased, network transformed from fibrous to more planar structures exhibiting a significant decrease in average pore size from 24 to 11 µm. G’ values of the crosslinked hydrogels were obtained between ~1 and ~5 kPa tuned by the crosslinking amount. Cell interaction properties of a select physical hydrogel prepared at 37 °C was tested using CCK-8 assay. It was observed that the keratose hydrogel supported L929 mouse fibroblast cell proliferation as much as collagen, which suggests that these keratose hydrogels can be promising candidates in soft tissue engineering applications.