title: Rationally Designed Redox-Sensitive Protein Hydrogels with Tunable Mechanical Properties.
abstract: Protein hydrogels are an important class of materials for applications in biotechnology and medicine. The fine-tuning of their sequence, molecular weight, and stereochemistry offers unique opportunities to engineer biofunctionality, biocompatibility, and biodegradability into these materials. Here we report a new family of redox-sensitive protein hydrogels with controllable mechanical properties composed of recombinant silk-elastin-like protein polymers (SELPs). The SELPs were designed and synthesized with different ratios of silk-to-elastin blocks that incorporated periodic cysteine residues. The cysteine-containing SELPs were thermally responsive in solution and rapidly formed hydrogels at body temperature under physiologically relevant, mild oxidative conditions. Upon addition of a low concentration of hydrogen peroxide at 0.05% (w/v), gelation occurred within minutes for the SELPs with a protein concentration of approximately 4% (w/v). The gelation time and mechanical properties of the hydrogels were dependent on the ratio of silk to elastin. These polymer designs also significantly affected redox-sensitive release of a highly polar model drug from the hydrogels in vitro. Furthermore, oxidative gelation was performed at other physiologically relevant temperatures, and this resulted in hydrogels with tunable mechanical properties, thus, providing a secondary level of control over hydrogel stiffness. These newly developed injectable SELP hydrogels with redox-sensitive features and tunable mechanical properties may be potentially useful as biomaterials with broad applications in controlled drug delivery and tissue engineering.
authors.affiliation: State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, People's Republic of China.
authors.forename: Ming-Liang
authors.initials: ML
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, People's Republic of China.
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Qian
authors.affiliation: State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, People's Republic of China.
authors.forename: Liang
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Biomedical Engineering, Tufts University , 4 Colby Street, Medford, Massachusetts 02155, United States.
authors.forename: David L
authors.initials: DL
authors.lastname: Kaplan
authors.affiliation: State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University , 800 Dongchuan Road, Shanghai 200240, People's Republic of China.
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Xia
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D001672:Biocompatible Materials / Q000737:chemistry* / Q000627:therapeutic use; D016503:Drug Delivery Systems; D004549:Elastin / Q000138:chemical synthesis / Q000737:chemistry* / Q000627:therapeutic use; D020100:Hydrogels / Q000138:chemical synthesis / Q000737:chemistry* / Q000627:therapeutic use; D055595:Mechanical Phenomena; D010084:Oxidation-Reduction; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry / Q000627:therapeutic use; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000627:therapeutic use; D047011:Silk / Q000737:chemistry* / Q000627:therapeutic use; D023822:Tissue Engineering
chemical_list: D001672:Biocompatible Materials; D020100:Hydrogels; D011108:Polymers; D011993:Recombinant Fusion Proteins; D047011:Silk; D004549:Elastin