Cationic gold microparticles for biolistic delivery of nucleic acids

μexceeding the 1 μg/mg limit of the conventional protocols. The binding showed no apparent μg/mg limit of the conventional protocols. The binding showed no apparent μ dependency on DNA purity, size, or conformation. The interaction occurred over a broad range of pH values and salt concentrations, and was stable throughout the standard protocol for biolistic cartridge preparation. At the standard 1 μg dose, biological activity of the DNA μg dose, biological activity of the DNA μ biolistically delivered on the charge-modified gold was 25% higher than that delivered on conventional microparticles. Loading the charge-modified gold with more DNA stimulated proportionally higher gene expression. The charge-modified gold can be also used for delivery of small biological molecules such as siRNA. Tissue culture cells biolistically transfected with a LUC+ specific siRNA showed 80% reduction of Luc expression relative to those cells transfected with an irrelevant siRNA. Along with its superior properties as a DNA delivery vehicle, charge-modified gold offers a unique opportunity to deliver various DNA formulations in addition to traditional naked DNA.