The potential of gene technology to revolutionize disease management by addressing their underlying causes is undeniable. Nevertheless, a substantial challenge lies ahead: the efficient administration of these treatments through the intricate physiological barriers of the human body. The aim of this research was to evaluate the potential of a supramolecular (SM), bioerodible and injectable hydrogel, composed of an ad−hoc engineered mixture of a custom synthetized poly(ether urethane) (PEU) and commercial α-cyclodextrins (CDs), as a conduit for localized gene therapy delivery. Specifically, two types of nanoparticle formulations encapsulating siRNA were examined: poly(lactic-co-glycolic acid) (PLGA) nanoparticles and poly(β-amino ester) (PBAE)-based polyplexes. The initial phase involved the characterization of the amphiphilic PEU, synthesized using Poloxamer®407 as a core component, in order to validate the persistence of its distinctive molecular attributes.