Physical and mechanical properties of thermosensitive xanthan/collagen-inspired protein composite hydrogels

ABSTRACT

Functionalization of xanthan hydrogels is of interest for biomaterial applications. The authors report characterization of electrostatic complexation of xanthan with a recombinant collagen-inspired triblock protein polymer. This polymer has one charged polylysine end-block that can bind to xanthan by electrostatic interactions, and another end-block that can self-assemble into thermosensitive collagen-like triple helices; the end-blocks are connected by a neutral, hydrophilic, mostly inert random coil. The protein modifies the xanthan/protein composite hydrogels in three ways: (a) a significant increase in storage modulus, (b) thermosensitivity, and (c) a two-step strain softening in nonlinear rheology.

GRAPHICAL ABSTRACT

KEYWORDS:

• Xanthan
• collagen-inspired protein
• composite hydrogels
• thermosensitivity
• strain-softening
• electrostatic interaction

Acknowledgments

The authors would like to thank A. Hernandez-Garcia for providing the (Lys)6-encoding dsDNA adapter and M. W. T. Werten for genetic cloning/fermentation.