Amphiphilic Poly[poly(ethylene glycol) methacrylate]s with OH Groups in the PEG Side Chains for Controlling Solution/Rheological Properties and toward Bioapplication.

Poly[poly(ethylene glycol) methacrylate]s with OH groups on the PEG side chains [poly(PEGOHMA)s] were synthesized using ruthenium-catalyzed living radical polymerization (Ru-LRP) to diversify the polymer design of PEGylated methacrylate-based copolymers. Poly(PEGOHMA)s could not be prepared using the approach previously reported for the synthesis of poly[poly(ethylene glycol) methyl ether methacrylate [poly(PEGMA)]; therefore, the polymerization was adapted for poly(PEGOHMA)s. As a result, both homopolymerization and random and block copolymerization of PEGOHMA with other hydrophobic monomers were successfully achieved, resulting in the preparation of amphiphilic random block and star polymers. The solution and bulk properties of PEGOHMA-based (co)polymers were markedly different from those of PEGMA-based (co)polymers. By reacting the OH groups with biotin, protein-poly(PEGOHMA) conjugates were successfully prepared; however, it was not possible to prepare protein-polymer conjugates using terminal biotinylated PEGMA-based copolymers, owing to the steric hindrance of the unreactive PEG side chains.