However, how the type of nucleic acid materials (RNA vs DNA) and their size impact on the binding capacity and kinetics, and in turn architecture of the resulting complexes remains unknown, despite the impact that such understanding may have on the delivery of different types of nucleic acid therapeutics. This report aims to elucidate these questions and identify the type of interactions and assemblies observed upon complexation of nucleic acid materials such as 20 base pair (bp) double stranded RNA or DNA, single stranded RNA, mRNA (with a size of 1000 bases) or plasmid DNA (pDNA) of 5230 bp. Whether primary adsorption or deep infiltration within brushes is achieved (Figure ) will be explored and the impact on adsorption kinetics and binding capacity will be discussed. To this aim, the adsorption of nucleic acid materials to PDMAEMA and PMETAC is characterised through surface plasmon resonance. This enabled the determination of kinetic parameters and the binding capacity of polymer brushes for the macromolecules investigated. In addition, adsorption was monitored via in situ ellipsometry to gain insight into changes in brush swelling upon complexation. To characterise changes in the morphology and position of nucleic acid materials at a greater resolution, the swelling of PDMAEMA prior and after complexation was monitored by neutron reflectometry. Together, these measurements allow identifying key kinetic, thermodynamic and structural features associated with the binding of nucleic acid macromolecules. Isabelle Freire Tabosa Viana (Aggeu Magalhães Institute, Oswaldo Cruz Foundation, Brazil).