Differences in molecular structure in cross-linked polycationic nanoparticles synthesized using ARGET ATRP or UV-initiated polymerization

This work compares material properties of polycationic nanoparticles synthesized using the techniques of UV-initiated polymerization or ARGET ATRP and relates differences in material properties to differences in molecular structure. The nanoparticles are based on the pH-responsive monomer 2-(diethylamino)ethyl methacrylate (DEAEMA) copolymerized with poly(ethylene glycol) methyl ether methacrylate (PEGMA), tert-butyl methacrylate (tBMA), and tetraethylene glycol dimethacrylate (TEGDMA) in a surfactant-stabilized monomer-in-water emulsion to form cross-linked nanoscale hydrogels. ARGET ATRP resulted in a narrower distribution of molecular weight for linear analogs of the polycationic nanoparticles. In addition, ARGET ATRP formulations showed a sharper glass transition than UV-initiated formulations, indicating increased homogeneity. These networks could be used as drug delivery carriers or for other nanogel applications that would benefit from polycationic nanoparticles with high homogeneity.