Characterization of elastic, thermo-responsive, self-healable supramolecular hydrogel made of self-assembly peptides and guar gum

Self-assembling peptides (SAPs) show great promise in regenerative medicine and beyond. Yet, their low mechanical rigidity and limited processability hinder many of their potential applications. In this work we describe the reinforcement of a synthetic biomimetic and β-sheet rich FAQRVPP-LDLK12 SAP by its integration with a naturally occurring polysaccharide - guar gum - to produce a shapeable and thermo-responsive composite hydrogel. Extensive characterization was performed via rheological measurements, CD spectroscopy, FT-IR spectroscopy, and AFM analyses. Composite hydrogels show preserved nanostructured morphology and cross-β structure aggregation typical of SAPs, improved mechanical properties (peaking at 1:1 weight ratio with G′~60 kPa) with self-healing and stress-relaxation propensities: they also exhibit reversible repeatable gel-sol transitions in response to thermal stimuli. Thanks to the dynamic properties of guar gum, stretchability was extended far beyond 5% strain of standard SAPs and processability allowed for the production of knotted threads and long (>10 cm) flexible sheets. Composite hydrogels of guar gum and SAPs may be added to the growing library of biomimetic SAP hydrogels used in 3D-printing, wound healing, suturing and beyond. Keywords: Self-assembling peptides, Guar gum, Supramolecular hydrogels, Self-healing, Thermal responsive, Nanofibers