Amphiphilic dendrigraft -caprolactone copolymers were prepared via the grafting reaction of polyethylene glycol chloroformate on the side and terminal hydroxyl groups of the dendrigraft poly(-caprolactone)s.The copolymers were characterized by 1H-NMR and GPC.1H-NMR analysis revealed that the graft rate was approximately 50%.GPC analysis showed that the molecular weight of the amphiphilic copolymers had a relatively narrow unimodal distribution.Their molecular weights were apparently increased comparing to the raw dendrigraft poly(-caprolactone)s.The amphiphilic copolymers were able to disperse directly in water forming micelles.The diameters of the micelles were measured by DLS to be in the range of 16 to 31 nm with moderate PDI of 0.25 to 0.39.The morphology of the micelles was observed by transmission electron microscopy (TEM).The micelle particles with an irregular globular shape were composed of smaller particles whose size is in accordance with the size of a single polymer molecule.In water

there might be an equilibrium between the unimolecular micelles and assembled multimolecular micelles.The amphiphilic copolymers showed high drug-loading capacity and drug encapsulation rate to hydrophobic antitumor drug pachitaxel

owing to the nano-sized cavities inside the dendrigraft structures.