A challenging approach to the application of multivalent interactions is the mimicry of functional biomacromolecules with therapeutic relevance. Several attempts have been made to mimic specific proteins, e.g., histones or polysaccharides like heparin. In these cases, mimicry is mostly based on the surface charge of the polymer molecules (Figure 1). In the particular case of dendritic PG, polyanionic derivates present similar activities to negatively charged polysaccharides, e.g., heparin, polysialic acid. The amine terminated PGs can act like histones to bind and compact DNA. Applications range from protein resistant coatings (neutral species) to DNA-transfection agents (polycationic systems), and anticoagulating and anti-inflammatory drugs (polyanionic systems).
The research goal is to establish by varying the nanoparticle size, degree of branching, and functionalization the systematic structure activity relationships between dendritic polyanions and polycations as mimics of proteins activity.