In contrast, densely charged polyelectrolyte brushes, such as those based on poly(dimethylaminoethyl methacrylate) (PDMAEMA) and poly(2methacrylolyloxyethyltrimethylammonium iodide) (PMETAI), are expected to promote strong interactions, in particular with low isoelectric point proteins, at neutral pH , a useful property to maximise loading of surfaces with enzymes, for example. In addition, polycationic brushes have found application for gene delivery, owing to their ability to capture negatively charged DNA and RNA macromolecules .