Abstract: An amphiphilic dendritic drug carrier compound 6-Arm MPEG-Drug Conjugate was designed and synthesized in which benzoic acid was used as model drug. The molecular structure was characterized by means of 1H NMR and 13C NMR spectroscopy. 1H NMR verified that 6-Arm MPEG-Drug Conjugate changed conformation in organic solvent and in aqueous solution. It assembled to nano-sized particle in aqueous solution. So the micelle characteristics of 6-Arm MPEG-Drug Conjugate in water were investigated by fluorescence spectroscopy, dynamic light scattering (DLS) and scanning electron microscopy (SEM). The critical micelle concentration (CMC) was determined by a fluorescence technique to be 2.5×10-2 mg/mL (5.3×10-6 mol/L); The hydrodynamic diameter of micelle was measured to be 67.4 nm at the concentration of 1.0 mg/mL by DLS and the polydispersity index (PDI) was estimated to be 0.106. In addition, 6-Arm MPEG-Drug Conjugate exhibited different aggregation behavior. It was found that tubes and microcubic particles could be formed at the different initial concentration. And it was interested that the aggregates morphological characteristics was changed from tubes to niosomes along with the addition of various contents of water.

Key words: drug carrier, micelle, niosome, amphiphilic, MPEG