title: Injectable, Biomolecule-Responsive Polypeptide Hydrogels for Cell Encapsulation and Facile Cell Recovery through Triggered Degradation.
abstract: Injectable hydrogels have been widely investigated in biomedical applications, and increasing demand has been proposed to achieve dynamic regulation of physiological properties of hydrogels. Herein, a new type of injectable and biomolecule-responsive hydrogel based on poly(l-glutamic acid) (PLG) grafted with disulfide bond-modified phloretic acid (denoted as PLG-g-CPA) was developed. The hydrogels formed in situ via enzymatic cross-linking under physiological conditions in the presence of horseradish peroxidase and hydrogen peroxide. The physiochemical properties of the hydrogels, including gelation time and the rheological property, were measured. Particularly, the triggered degradation of the hydrogel in response to a reductive biomolecule, glutathione (GSH), was investigated in detail. The mechanical strength and inner porous structure of the hydrogel were influenced by the addition of GSH. The polypeptide hydrogel was used as a three-dimensional (3D) platform for cell encapsulation, which could release the cells through triggered disruption of the hydrogel in response to the addition of GSH. The cells released from the hydrogel were found to maintain high viability. Moreover, after subcutaneous injection into rats, the PLG-g-CPA hydrogels with disulfide-containing cross-links exhibited a markedly faster degradation behavior in vivo compared to that of the PLG hydrogels without disulfide cross-links, implying an interesting accelerated degradation process of the disulfide-containing polypeptide hydrogels in the physiological environment in vivo. Overall, the injectable and biomolecule-responsive polypeptide hydrogels may serve as a potential platform for 3D cell culture and easy cell collection.
authors.affiliation: Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, P.R. China.|University of Chinese Academy of Sciences , Beijing 100039, P.R. China.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, P.R. China.
authors.forename: Chaoliang
authors.initials: C
authors.lastname: He
authors.affiliation: Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, P.R. China.|University of Chinese Academy of Sciences , Beijing 100039, P.R. China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, P.R. China.
authors.forename: Kaixuan
authors.initials: K
authors.lastname: Ren
authors.affiliation: Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences , Changchun 130022, P.R. China.
authors.forename: Xuesi
authors.initials: X
authors.lastname: Chen
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D006735:Horseradish Peroxidase; D020100:Hydrogels; D010455:Peptides / Q000737:chemistry*; D051381:Rats; D012212:Rheology
chemical_list: D020100:Hydrogels; D010455:Peptides; D006735:Horseradish Peroxidase
keywords: biomolecule-responsive hydrogel; cell recovery; enzymatic cross-linking; polypeptide hydrogel; triggered degradation