Hybrid nanoparticles based on lactide and poly(ethylene glycol) were composed of a copolymer, poly(2-amino, 1,3-propanediol carbonic ester-co-lactide) [P(LA-co-CA)], and a graft copolymer, poly(2-amino, 1,3-propanediol carbonic ester-co-L-lactide)-g-methoxy-poly(ethylene glycol) [P(LA-co-CA)-mPEG]. The hybrid nanoparticles were prepared using emulsion solvent diffusion method. The copolymer of poly(2-benzyloxy amide, 1,3-propanediol carbonic ester-co-lactide) was prepared using ring-opening polymerization with diethylzinc (ZnEt2) as a catalyst, and then took off benzyl oxygen group to obtain P(LA-co-CA). P(LA-co-CA)mPEG by grafting methoxy-PEG-propionaldehyde (mPEG-ALD) on P(LA-co-CA). With docetaxel as a model drug, the morphology of nanoparticles was characterized by scanning electron microscopy (SEM) and the size and size distribution were determined by dynamic light scattering (DLS). The size of DTX-loaded particle was approximately 110 nm. The size scale prevents them from uptake by the reticulo-endothelial system and accumulation at the target site through the enhanced permeability and retention effect. In MTT assay, the results showed that the polymers are non-cytotoxic. The study points to the potential application of the composite nanoparticles in biomedical applications, including tissue engineering and controlled drug delivery. (C) 2014 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.