Amphiphilic Toothbrushlike Copolymers Based on Poly(ethylene glycol) and Poly(ε-caprolactone) as Drug Carriers with Enhanced Properties

Amphiphilic poly(ethylene glycol)-b-poly(2-hydroxyethyl methacrylate-g-poly(e-caprolactone)) (PEG-b-P(HEMA-g-PCL)) toothbrushlike copolymers were synthesized and evaluated as drug delivery carriers. Two toothbrushlike polymers were synthesized via ring-opening polymerization of e-caprolactone (CL) initiated by poly(ethylene glycol)-b-poly(2-hydroxyethyl methacrylate) (PEG-b-PHEMA) macromolecular initiators, and their molecular structures and physical properties were characterized using 1H NMR, gel permeation chromatography (GPC), and differential scanning calorimetric analysis (DSC). The melting points and crystallizable temperature have been decreased obviously, implying that the PCL cores of PEG-b-P(HEMA-g-PCL) toothbrushlike copolymer micelles with shorter PCL segments were unlikely to crystallize at room temperature for drug delivery application. Also the micellization properties of toothbrushlike copolymers in aqueous solution were investigated by fluorescence spectroscopy, dynamic light scattering (...