Methoxy poly(ethylene glycol)-b-poly(L-lactic acid) (MPELLA) was prepared by the melt polycondensation of methoxy poly(ethylene glycol) and L-lactic acid. The structure and properties of MPELLA were characterized by IR, H-1-NMR, differential scanning calorimetry, and wide-angle X-ray diffraction. To estimate its feasibility as a vehicle for paclitaxel, MPELLA nanoparticles were prepared by a self-emulsification/solvent evaporation method. The paclitaxel-loaded nanoparticles (PMTs) showed a spherical morphology with an inner core and an outer shell. The size, size distribution, and loading capacity of PMTs were also measured. The release kinetics of paclitaxel from PMTs in vitro was studied. The results show that paclitaxel can be effectively incorporated into MPELLA nanoparticles, which provide a delivery system for paclitaxel and other hydrophobic or toxic compounds. (c) 2005 Wiley Periodicals, Inc.