Fig. 5

Controllers that direct hydrogel expansion in response to different types of chemical inputs. a An aptamer-containing strand-displacement circuit that releases Catalyst in response to ATP. b Solution kinetics of the circuit in (a) measured using fluorescence reporting (see Methods, Supplementary Fig. 19) in response to different ATP concentrations. ATP sensor, Cofactor, and Catalyst source initially at 100 nM. c ATP-controlled rates of particle swelling mediated by the circuit in (a), catalytic crosslink unlocking (Fig. 3a), and hairpin polymerization (Fig. 1c). Sensor, Cofactor, and Catalyst source at 100 nM; Helper strand at 10 µM. d DNA strand-displacement AND logic circuit. Two inputs, F_in and G_in, are required for Catalyst release. e Kinetics of the logic circuit in (d) in solution measured by fluorescence reporting. The logic gate and Catalyst source are at 200 nM. f Particle expansion in the presence of different F_in and G_in concentrations. Logic gate and Catalyst source are at 200 nM; Helper at 10 µM. N = 3 (b, e) or 2–6 c, f. Shaded regions (b, e) represent 95% confidence intervals determined by standard deviations; dotted lines in (c, f) are replicate measurements with the averages represented by solid lines