@article { ISI:000304492700037,
	title = {A Facile Way to Tune Mechanical Properties of Artificial Elastomeric Proteins-Based Hydrogels},
	journal = {LANGMUIR},
	volume = {28},
	number = {21},
	year = {2012},
	month = {MAY 29},
	pages = {8260-8265},
	abstract = {Protein-based hydrogels have attracted considerable interests due to their potential applications in biomedical engineering and material sciences. Using a tandem modular protein (GB1)(8) as building blocks, we have engineered chemically cross-linked hydrogels via a photochemical cross-linking strategy, which is based on the cross-linking of two adjacent tyrosine residues into dityrosine adducts. However, because of the relatively low reactivity of tyrosine residues in GB1, (GB1)(8)-based hydrogels exhibit poor mechanical properties. Here, we report a Bolton Hunter reagent-based, facile method to improve and tune the mechanical properties of such protein-based hydrogels. Using Bolton Hunter reagent, we can derivatize lysine residues with phenolic functional groups to modulate the phenolic (tyrosine-like) content of (GB1)(8). We show that hydrogels made from derivatized (GB1)(8) with increased phenolic content show significantly improved mechanical properties, including improved Young{\textquoteright}s modulus, breaking modulus as well as reduced swelling. These results demonstrate the great potential of this derivatization method in constructing protein-based biomaterials with desired macroscopic mechanical properties.},
	issn = {0743-7463},
	doi = {10.1021/la301225w},
	author = {Fang, Jie and Li, Hongbin}
}
