Objective. To evaluate the possibility and efficiency of nanoparticle as a new vector in specific gene transference.Methods. Nanoparticle-DNA complex was prepared with Poly- dl-lactic-co-glycolic acid （PLGA） bearing anti-sense monocyte chemotactic protein-1 （A-MCP-l）

a specific expression gene

and the package efficiency

release progress in vitro

and the size of the complex were determined. The possibility of the new vector was evaluated with genomic DNA PCR by transferring gene into cultured smooth muscle cells （SMC）

cationic lipids as a control. For study in vivo

jugular vein-to-artery bypass grafting procedures were performed on 20 New Zealand white rabbits

of which 6 grafts were transferred with nanoparticle-A-MCP-1 （200 μg）

6 with A - MCP-1 （200 μ g） by cationic liposome

4 with LNCX plasmid

and 4 as control. Fourteen days after the grafts were harvested

the expression of A-MCP-l and its effect on MCP-1 in vein grafts were detected by dot blot

and the morphologic evaluation of grafts was performed.Results. The package efficiency of the nanoparticle-DNA complex was 0. 9%

release progress in vitro lasted 2 weeks

and the size ranged from 150 to 300nm. SMC genomic DNA PCR showed that A-MCP-l gene could be successfully transfected into cells by nanoparticle. The study in vivo indicated that A-MCP-l mRNA was expressed in both local gene delivery groups

nanoparticle and liposome

meanwhile

MCP-1 expression in vein grafts was significantly inhibited and neointimal hyperplasia was notably reduced.Conclusion. Nanoparticle can act as a vector to transfect specific gene.