Active DNA Hydrogels

Active gels are exotic smart materials that consume energy to actuate and/or change their material properties. DNA nanostars hydrogels have now been extensively studied as prototypical examples of equilibrium gels, yet their enhancement using proteins or energy-consuming processes has been overlooked so far. In this talk, I will describe our combined experimental and computational work in designing and characterising generic active DNA hydrogels. More specifically, I will report on recent results that we obtained by encoding a different number of specific restriction sites on the arms of the DNA nanostars. Thanks to endonuclease specificity, we can carefully tune the rate and pathway through which DNA hydrogels dissolve and modulate their viscoelastic properties in time. I will present data using passive/active microrheology and confocal microscopy to characterise the temporal evolution of the hydrogels viscoelasticity and oxDNA-based computational models to rationalise our observations . These models are promising to be a key tool in the designing of the next generation of hydrogels. Our work paves the way for DNA-based scaffolds and drug-delivery systems with continuously time-varying rheology.