Alternative delivery entities are desirable in immunotherapies in which polyplexes are widely formed by electrostatic interactions to induce cellular uptake processes for bioactive molecules. In our study, biocompatible Ni(II)-nitrilo(triacetic acid)-modified poly(ethylene imine)-maltose (Ni-NTA-DG) is realized and evaluated as complexation agent against His-tagged peptides using fluorescence polarization and dynamic light scattering. The polyplexes are stable until a pH of 6.56.0, and also up to 50mM of imidazole. A first uptake approach shows that polyplexes lead to an increase in peptide uptake in monocyte-derived immature dendritic cells. In summary, Ni-NTA-DG represents a promising (delivery) platform for forthcoming in vitro applications.