Figure 2.

Rheological characterization of hydrogels to demonstrate thixotropy and injectability. (A) Strain sweep of peptide hydrogels show a relatively high storage modulus (G′) of about 400 Pa, which is decimated above ∼10% strain. At this point the values for G″ exceed G′ indicating liquefaction. (B) Hydrogels are allowed to equilibrate at a constant frequency of 1 Hz and 1% strain rate. As the strain is instantaneously increased to 100%, inversions of G′ and G″ occur suggesting instantaneous liquefaction of the gel. Interestingly, after removing the high deformation strain, 100% of the storage modulus is recovered within 3 s. (C) This is evident while pipetting the gel onto the rheometer stage where instantaneous gelation leaves a nubbin suspended with its reflection visible.