H-Shaped copolymer ((His)PHEMA)2-b-PEG-b-(PHEMA(His))2 with histidine modified: Synthesis, characterization and its drug release study

Through H-shaped macroinitiator glycol-chlorine((Cl) 2 -PEG-(Cl) 2 ) to initiate the ATRP reaction of 2-Hydroxyethyl Methacrylate (HEMA) we synthesized H-shaped copolymer (PHEMA) 2 - b -PEG- b -(PHEMA) 2 . After we modified the copolymer with histidine (His), the self-assembling and drug release behavior was studied. The morphology of the copolymer micelles and drug loaded micelles were examined by transmission electron microscope (TEM). Spherical micelles and core-shell structure with a diameter of 165 nm were obtained (at pH = 7.0). Due to the presence of imidazole-ring in histidine the copolymer show commendable pH-sensitivity, which made the copolymer potential application as drug carrier exhibiting good control-released property.