AIM:To investigate the preparation,physicochemical characterization and cytotoxicity in vitro of Gemcitabine-loaded poly(ethylene glycol)-block-poly(D,L-lactide) (PEG-PDLLA) nanovesicles. METHODS:The nanovesicle carriers were prepared from the amphiphilic block copolymer of PEG-PDLLA by a double emulsion technique,and gemcitabine was used as the model drug. The morphology of the nanovesicles was determined by scanning and transmission electron microscopy,and the drug content,drug entrapment and drug-release curve in vitro were detected by UV-Vis-NIR spectrophotometry. Cytotoxicity in the human pancreatic cancer cell line SW1990 was tested by 3-(4,5-dimethyl) ethiazole (MTT) assay.RESULTS:The gemcitabine-loaded nanovesicles were hollow nanospheres with a mean size of 200.6 nm,drugloading of 4.14% and drug embedding ratio of 20.54%. The nanovesicles showed excellent controlled release that was characterized by a fast initial release during the first 72 h,followed by a slower and continuous release. The MTT assay demonstrated that gemcitabine-loaded nanovesicles exhibited dose-dependent and time-delayed cytotoxicity in the human pancreatic cancer cell line SW1990.CONCLUSION:Gemcitabine-loaded PEG-PDLLA nanovesicles prepared by a double emulsion technique exhibited good performance for controlled drug release,and had similar cytotoxic activity to free gem-citabine. To investigate the preparation, physicochemical characterization and cytotoxicity in vitro of Gemcitabine-loaded poly (ethylene glycol) -block-poly (D, L-lactide) (PEG-PDLLA) nanovesicles. METHODS: The nanovesicle carriers were prepared from the amphiphilic block morphology of PEG-PDLLA by a double emulsion technique, and gemcitabine was used as the model drug. The morphology of the nanovesicles was determined by scanning and transmission electron microscopy, and the drug content, drug entrapment and drug-release curve in vitro were detected by UV-Vis-NIR spectrophotometry. Cytotoxicity in the human pancreatic cancer cell line SW1990 was tested by 3- (4,5-dimethyl) ethiazole (MTT) assay.RESULTS: The gemcitabine- loaded nanovesicles were hollow nanospheres with a mean size of 200.6 nm, drugloading of 4.14% and drug embedding ratio of 20.54%. The nanovesicles showed excellent controlled release that was characterized by a fast initial release during the first 72 h, followed by a slower and continuo us release. The MTT assay demonstrated that gemcitabine-loaded nanovesicles showed dose-dependent and time-delayed cytotoxicity in the human pancreatic cancer cell line SW1990. CONCLUSION: Gemcitabine-loaded PEG-PDLLA nanovesicles prepared by a double emulsion technique showed good performance for controlled drug release, and had similar cytotoxic activity to free gem-citabine.