Triple redox/temperature responsive diselenide‐containing homopolypeptide micelles and supramolecular hydrogels thereof. Issue 10 (22nd February 2018) - Gao, Yuanfeng
ABSTRACT: Stimuli‐responsive polypeptides are receiving much attention for drug delivery systems and tissue engineering scaffolds; however, it is challenging to construct multiple‐responsive polypeptides and one‐component polymeric hydrogels. Herein, a novel type of triple redox/temperature‐responsive diselenide‐containing poly(methoxydiethylene glycol‐l ‐glutamate) homopolypeptide was facilely synthesized by selenocystamine‐initiated ring‐opening polymerization in DMF at 30 °C, and their chemical structures and physical properties were fully characterized by means of 1 H NMR, GPC, FT‐IR, WAXD, and CD. They self‐assembled into spherical micelles in aqueous solution, which possess a lower critical solution temperature, redox‐responsiveness inherited from diselenide bond, and the triple stimuli‐sensitive self‐assembly behaviors, as characterized by means of turbidity, DLS, TEM, and zeta potential measurements. The diselenide‐containing homopolypeptides formed supramolecular hydrogels at room temperature, exhibiting a thermal gel–sol transition. The rheological tests evidence that the mechanical modulus of the hydrogel is independent of angular frequency within 100 rad/s and at 25 °C, in which the storage modulus of G′ is order of magnitude greater than the loss modulus of G″, displaying a solid‐like elastic behavior. Moreover, the mechanical modulus of the hydrogel can be tuned by changing the chain length of the homopolypeptide, the 10‐mM 1, 4‐dithiothreitol (DTT) reduction, and 1 mM H2 O2 oxidation, respectively. Consequently, this work provides a simple strategy to fabricate triple‐stimuli responsive polypeptide micelles and one‐component hydrogels. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem.2018, 56, 1067–1077 Abstract : A novel type of triple redox/temperature‐responsive diselenide‐containing poly(methoxydiethylene glycol‐l ‐glutamate) homopolypeptide was facilely synthesized, which exhibited triple stimuli‐sensitive self‐assembly behaviors. The diselenide‐containing homopolypeptides formed supramolecular hydrogels and the mechanical modulus can be tuned by changing the chain length of the homopolypeptide, the 10‐mM 1, 4‐dithiothreitol reduction, and 1 mM H2 O2 oxidation, respectively. Consequently, this work provides a simple strategy to fabricate triple‐stimuli responsive polypeptide micelles and one‐component hydrogels.