In this study, we synthesized four kinds of poly(D,L-lactide-co-glycolide) (PLGA) and Pluronic nanoparticles of paclitaxel (PTX-NPs) and evaluated surface modification dependent cellular response and pharmacokinetic. Atomic force microscopy, dynamic light scattering, live cell confocal microscopy, and high-performance liquid chromatography were used to characterize PTX-NPs and compare their in vitro cellular behavior and in vivo pharmacokinetic. The cytotoxicity of PTX-NPs treated bone marrow derived macrophages (BMM), U87 and astrocytes were analyzed by MTT analysis. The inner immune responses of BMM were examined by RT-PCR. All resultant PTX-NPs had spherical shape and high encapsulation efficiency. Cellular uptake of the PTX-NPs conjugated with poly (ethylene glycol) (PEG) or Folate was higher than that of non-modified PTX-NPs. In vitro cytotoxicity studies revealed that the PTX-NPs modified with PEG or folic acid provided greater chemosensitivities to cancer cells than those of nonmodified PTX-NPs. RT-PCR results showed that PLGA NP with PEG modification exhibited lower levels of inner immune responses. Cytoarchitecture studies demonstrated a similar cytoskeleton pattern before and after PTX-NPs loaded into BMM. In vivo pharmacokinetic results indicated that the PTX-NPs with hydrophilic shell of PEG had longer systemic circulation time and slower plasma elimination rate. These results concluded that surface modification of PTX-NPs with PEG or Folate could influence in vitro cellular behavior and in vivo pharmacokinetic. (C) 2012 Elsevier Ltd. All rights reserved.