A full spectrum of proof-of-concept research from nanoparticle preparation and characterization, in vitro drug release, cellular uptake and cytotoxicity, to in vivo pharmacokinetics and xenograft tumor model is developed in this paper to demonstrate how nanoparticles of biodegradable polymers can be applied to formulate anticancer drugs to avoid use of toxic adjuvant and to enable sustained and controlled chemotherapy. Paclitaxel-loaded poly(lactic-co-glycolic acid) nanoparticles were prepared by solvent extraction/evaporation with vitamin E TPGS as the emulsifier, which has much higher emulsification effects and better biocompatibility than other chemical emulsifiers such as polyvinyl alcohol (PVA), resulting in a high drug encapsulation efficiency, high uptake of nanoparticles by cancer cells, and sustainable pharmacokinetics. In vitro C6 cell mortality experiments demonstrated that the nanoparticle formulation was five times more effective than Taxol (R). In vivo pharmacokinetics measurements showed that the nanoparticle formulation had a comparable value of the area-under-the-curve (AUC) with that of Taxol (R), but never exceeded the maximum tolerance level, and hence should greatly reduce the side effects compared with Taxol (R). Moreover, the nanoparticle formulation realized a sustainable therapeutic time of 168 h in comparison with 22 h for Taxol (R) at a same dose of 10 mg/kg and achieved four times greater drug tolerance than Taxol (R). (C) 2007 Elsevier Ltd. All rights reserved.