ObjectiveTo clone and construct a eukaryotic expression vector of human bone morphogenetic protein (BMP) 2 and histidine in vitro and synthesize chitosan (CS)/pIRES2-EGFP-hBMP2-His nanoparticles.MethodspMD18T-hBMP2-His was digested by EcoRⅠand BamHⅠto obtain the hBMP2-His gene, which was inserted into pIRES2-EGFP to form pIRES2-EGFP-hBMP2-His. Afterward, CS, which exhibited five different molecular weights and deacetylation degrees, was complexed with pIRES2-EGFP-hBMP2-His to form CS/pIRES2-EGFP-hBMP2-His nanoparticles; in this procedure, a desolvent method was used at different N/P ratios (amino in CS to phospho in plasmid DNA). The gene-encapsulating ability of CS was evaluated by agarose gel electrophoresis and fluorescence spectrophotometry; size, distribution, and potential were analyzed using a ZetaPALS analyzer. The shape of the nanoparticles was observed under an atomic force microscope.Results1) pIRES2-EGFP-hBMP2-His was constructed after the cloned hBMP2-His gene was confirmed by sequencing. 2) CS/pIRES2-EGFP-hBMP2-His nanoparticles were synthesized and pIRES2-EGFP-hBMP2-His was packaged by CS. 3) CS/pIRES2-EGFP-hBMP2-His nanoparticles were globular with an average size of 111.7 nm to 3 214.2 nm and an average zeta-potential of 4.93 mV to 16.79 mV.Conclusion CS/pIRES2-EGFP-hBMP2-His nanospheres are successfully synthesized.