Plasmid DNA on nanoparticles offers effective delivery of antigen.(Brief Article)

2002 OCT 2 - (NewsRx.com & NewsRx.net) -- by Maria G. Essig, MS, ELS, senior medical writer - Nanoparticles coated with plasmid DNA (pDNA) stimulated a stronger immune response in a murine model than did "naked" plasmid DNA, according to researchers in Kentucky.

"Genetic immunization using 'naked' plasmid DNA (pDNA) has been shown to elicit broad humoral and cellular immune responses," explained Zhengrong R. Cui and Russell J. Mumper at the University of Kentucky. "However, more versatile and perhaps cell-targeted delivery systems are needed."

Cui and Mumper synthesized spherical cationic nanoparticles (100 nm in diameter) through an oil-in-water emulsion process with wax as the oil phase and cetyltrimethylammonium bromide (CTAB) as the surfactant. The surface of the nanoparticles was coated with pDNA expressing beta-galactosidase. Studies showed the nanoparticles were stable for 30 minutes at 37 degree C.

After addition of an endosome-disrupting lipid and/or a dendritic cell-targeting ligand (mannan), the PDNA-coated nanoparticles were subcutaneously injected into BALB/c mice. Twenty-eight days later, the resulting specific IgG antibody immune response was 16 times greater than that found for "naked" pDNA ...