| Autor: |
Silva OA; Department of Chemistry, State University of Maringa, Maringa 87020-900, PR, Brazil., Rossin ARS; Department of Chemistry, State University of Maringa, Maringa 87020-900, PR, Brazil.; Postgraduate Program in Chemistry, State University of West Paraná, Toledo 85903-000, PR, Brazil., Lima AMO; Department of Chemistry, State University of Maringa, Maringa 87020-900, PR, Brazil.; Research Laboratory, Federal Institute of Maranhão-Imperatriz, Imperatriz 65900-000, MA, Brazil., Valente AD; Department of Basic Health Sciences, State University of Maringa, Maringa 87020-900, PR, Brazil., Garcia FP; Department of Basic Health Sciences, State University of Maringa, Maringa 87020-900, PR, Brazil., Nakamura CV; Department of Basic Health Sciences, State University of Maringa, Maringa 87020-900, PR, Brazil., Follmann HDM; Department of Chemistry, State University of Maringa, Maringa 87020-900, PR, Brazil., Silva R; Department of Chemistry, State University of Maringa, Maringa 87020-900, PR, Brazil., Martins AF; Department of Chemistry, State University of Maringa, Maringa 87020-900, PR, Brazil.; Laboratory of Materials, Macromolecules, and Composites, Federal University of Technology-Paraná, Apucarana 86812-460, PR, Brazil.; Department of Chemistry, Pittsburg State University, Pittsburg, KS 66762, USA. |
| Abstrakt: |
Human hair, composed primarily of keratin, represents a sustainable waste material suitable for various applications. Synthesizing keratin nanoparticles (KNPs) from human hair for biomedical uses is particularly attractive due to their biocompatibility. In this study, keratin was extracted from human hair using concentrated sulfuric acid as the hydrolysis agent for the first time. This process yielded KNPs in both the supernatant (KNPs-S) and precipitate (KNPs-P) phases. Characterization involved scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), Zeta potential analysis, X-ray diffraction (XRD), and thermogravimetric analysis (TG). KNPs-S and KNPs-P exhibited average diameters of 72 ± 5 nm and 27 ± 5 nm, respectively. The hydrolysis process induced a structural rearrangement favoring β-sheet structures over α-helices in the KNPs. These nanoparticles demonstrated negative Zeta potentials across the pH spectrum. KNPs-S showed higher cytotoxicity (CC 50 = 176.67 µg/mL) and hemolytic activity, likely due to their smaller size compared to KNPs-P (CC 50 = 246.21 µg/mL), particularly at concentrations of 500 and 1000 µg/mL. In contrast, KNPs-P did not exhibit hemolytic activity within the tested concentration range of 32.5 to 1000 µg/mL. Both KNPs demonstrated cytocompatibility with fibroblast cells in a dose-dependent manner. Compared to other methods reported in the literature and despite requiring careful washing and neutralization steps, sulfuric acid hydrolysis proved effective, rapid, and feasible for producing cytocompatible KNPs (biomaterials) in single-step synthesis. |
