Objective: To evaluate the possibility and efficiency of nanoparticle as a new vector in specific gene transference.
Methods: Nanoparticle-DNA complex was prepared with PLGA bearing antisense monocyte chemotactic protein-1 (A-MCP-1), a specific expression gene, and the package efficiency, release progress in vitro, and size of the complex were determined. The nanoparticl-DNA was trasnsfected into the cultured smooth muscle cells. PCR was used to evaluate the transfection of A-MCP-1. Cationic lipid (lipofectamine) was used to transfect A-MCP-1 as control. Forty-eight hours later, DNA in the SMCs was extracted and examined by PCR. Twenty New Zealand White rabbits underwent jugular vein-to-artery bypass grafting procedure, of which 6 received grafts transfected with nanopaticle-A-MCP-1 (200 microgram), 6 received grafts with cationic liposome (DOTAP)-A-MCP-1 (200 microgram), 4 received grafts with LNCX plasmid, and 4 received grafts without transfection as control. Fourteen days after surgery grafts were harvested. The expression of A-MCP-1 and its effect on MCP-1 in vein grafts were detected by dot blotting. The morphology of the grafts was investigated.
Results: The package efficiency, release progress in vitro, and size of the nanoparticle-DNA complex thus prepared were 0.9%, 2 week, and 150 nm approximately 300 nm respectively. Genomic DNA PCR showed that A-MCP-1 gene could be successfully transfected into smooth muscle cells by nanoparticle. Two weeks later, antisense MCP-1 was expressed in the vascular walls of the groups with transfection methods by nanaoparticle or by cationic lipid to an almost same degree. The degree of vascular hyperplasia in gene transfection groups was lower than that in control group. There was no significant difference in inhibition of intimal hyperplasia between the two groups of transfection by different vectors.
Conclusion: Nanoparticle acts as a vector to transfect specific gene in vitro and in vivo.