Stimulus-responsive DNA-hydrogels with swelling capabilities are a promising class of materials for biomedical applications such as drug delivery and biosensing. Designing these systems remains challenging because fabrication methods must be simultaneously biocompatible and conserve scarce DNA materials, even at the microscale. Moreover, stimulus-induced swelling must be precisely controlled and shown to drive measurable changes in molecular properties. We present a biocompatible fabrication and characterization method for micron-scale DNA-hydrogels with tunable isotropic swelling and dissolving properties. We first developed a fabrication method demonstrating that both the hydrogel composition and the fabrication process itself are biocompatible, while also minimizing the consumption of valuable DNA reagents. We then demonstrated modular control over isotropic swelling in micron-scale DNA microgels, achieving up to a two-fold size increase with tunable swelling through defined design parameters. We further established a quantitative workflow to measure structural changes of spherical, swollen and unswelled microgels leveraging the diffusive properties of a DNA-binding dye. Finally, we demonstrate tunable dissolving of microgels and quantitatively reveal various experimental factors that influence dissolution rates beyond what is traditionally considered in microgel experiments. Together, these advances establish a biocompatible platform for the fabrication and analysis of stimulus-responsive DNA micro-hydrogels, providing a foundation for their future use in drug delivery, biosensing, and related biomedical technologies.
Categories: cond-mat.soft