pH and ion-selective swelling behaviour of keratin and keratose 3D hydrogels

GALABURRI, GONZALO; PERALTA RAMOS, MARÍA L.; LÁZARO-MARTÍNEZ, JUAN M.; FERNÁNDEZ DE LUIS, ROBERTO; ARRIORTUA, MARÍA ISABEL; VILLANUEVA, MARÍA E.; COPELLO, GUILLERMO J.

EUROPEAN POLYMER JOURNAL

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2019 vol. 118 p. 1 - 9

0014-3057

The oxidation of keratin hydrogels was optimized aiming to obtain keratose hydrogels while maintaining theoriginal 3D structure and pH-responsive behaviour. In addition, we present a comparative study of their dualstimuliresponsive behaviour regarding the pH-responsiveness and their previously non-described ion selectiveresponsiveness. Keratose and keratin hydrogels showed similar swellings when contracted at low pH, and theformer showed steeper expansion and higher swelling than the latter at high pH. In addition, both hydrogelsshowed selective responsiveness toward Ca2+ ions when expanded, and toward Cu2+ ions when contracted. IR,Raman, ss-NMR, HRMAS NMR, SAXS, and thermal characterization demonstrated that oxidation does not interferewith the stimuli-responsive mechanisms related to protein conformation. The higher swelling of keratosehydrogels would be originated in the increase of the mobility of the chains after oxidation coupled to thehydration of sulfonic acid groups