Sustainable and smart keratin hydrogel with pH-sensitive swelling and enhanced mechanical properties

• Published in: Materials Science & Engineering C Vol. 78; pp. 619 - 626
• Main Authors: Peralta Ramos, María Luz, González, Joaquín Antonio, Fabian, Lucas, Pérez, Claudio Javier, Villanueva, María Emilia, Copello, Guillermo Javier
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.09.2017; Elsevier BV
• Subjects: Agricultural wastes; Biocompatibility; Biocompatible Materials; Biodegradability; Biodegradable materials; Biodegradation; Biomaterial; Biomaterials; Biomedical materials; Feathers; Horns; Hydrogel; Hydrogels; Hydrogels - chemistry; Hydrogen ions; Hydrogen-Ion Concentration; Keratin; Keratins; Low cost; Materials science; Mechanical properties; pH effects; Reagents; Smart material; Stimuli-responsive; Surgical implants; Swelling; Wool; Stimuli-responsive; Keratin; Biomaterial; Hydrogel; Smart material
• ISSN: 0928-4931; 1873-0191
• DOI: 10.1016/j.msec.2017.04.120

Protein based hydrogels are a very interesting type of biomaterials with many probed strengths related to their source and chemical structure. Biocompatibility and biodegradability are accompanied by affordability when it comes to low cost sources. The main keratin source is agroindustrial waste, such as feathers, horns, hooves, hair and wool. Thus, the main cost of keratin hydrogels derives from their processing. Here is presented a new strategy for the obtaining of a keratin hydrogel with enhanced mechanical properties using low cost reagents. This keratin hydrogel is stiff enough to allow handling without special cares and also presenting a reversible pH-responsive behavior. The minimum swelling is observed at low pH due to a collapsed and disordered protein network with water tightly adsorbed to the hydrophilic sites. The swelling rises significantly above pH6 and the maximum swelling appears above pH8 where an expanded network allows water to enter to the pores. [Display omitted] •A novel method for keratin hydrogel obtaining is presented.•This is a green and low cost method that uses aqueous media and ethanol as reagents.•This is a sustainable process that reuses agroindustrial waste as keratin source.•This keratin hydrogel is endowed with pH-responsive reversible swelling.•Chain reorganization instead of electrostatic repulsion drives the swelling response.