Figure 3.
pH-dependent rheological analysis of PIC-DNA cross-linked with 0.9 equiv of DNA LC at 30 °C in PBS, 10 × 10–3 M MgCl2. (a) The i-motif (green trace), incorporated in the DNA cross-linker LC, is in an extended state at pH 7.4 and contracts at pH 5.2; (b) CD spectra to characterize the conformation of the i-motif sequence in the PIC-DNA hydrogel at pH 7.4 (blue) and pH 5.2 (green); (c) Time evolution of storage modulus G′ after addition of DNA cross-linker LC at pH 7.4 (blue) and pH 5.2 (green); (d) K′/G0 as a function of σ at pH 7.4 (blue) and pH 5.2 (green).