Size Tunable Core Crosslinked Micelles from HPMA-Based Amphiphilic Block Copolymers

A variety of core crosslinkable hydroxypropylmethacrylamide-based block copolymers are synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization, which are composed of hydroxypropyl-methacrylate as hydrophilic block combined with a statistical hydrophobic block from laurylmethacrylate and the photo crosslinkable monomer. It is discovered that the self-assembled micellar aggregates from these systems vary strongly in size depending not only on the velocity of the polarity switch (nanoprecipitation or slow dialysis) but also on the solvent from which they were dialyzed. In this way micellar aggregates with an R-h varying between 15 and 80 nm can be prepared from the same block copolymer. In addition, a new hydrophobic crosslinkable hymecromone moiety is introduced. In this way the differently sized nanoparticles can be effectively stabilized by photo-crosslinking, leading to a high stability of the photo crosslinkable polymeric micelles against disintegration by detergents.