Biodistribution, metabolism, and in vivo gene expression of low molecular weight glycopeptide polyethylene glycol peptide DNA co-condensates

The biodistribution, metabolism, cellular targeting, and gene expression of a nonviral peptide DNA gene delivery system was examined. I-125-labeled pl asmid DNA was condensed with low molecular weight peptide conjugates and do sed i.v, in mice to determine the influence of peptide DNA formulation para meters on specific gene targeting to hepatocytes. Optimal targeting to hepa tocytes required the combined use of a triantennary glycopeptide (Tri-CWK18 ) and a polyethylene glycol-peptide (PEG-CWK18) to mediate specific recogni tion by the asialoglycoprotein receptor and to reduce nonspecific uptake by Kupffer cells. Tri-CWK18/PEG-CWK18 DNA co-condensates were stabilized and protected from metabolism by glutaraldehyde crosslinking. An optimized form ulation targeted 60% of the dose to the liver with 80% of the liver targete d DNA localized to hepatocytes. Glutaraldehyde crosslinking of DNA condensa tes reduced the liver elimination rate from a t(1/2) of 0.8 to 3.6 h. An op timized gene delivery formulation produced detectable levels of human alpha (1)-antitrypsin in mouse serum which peaked at day 7 compared to no express ion using control formulations. The results demonstrate the application of formulation optimization to improve the targeting selectivity and gene expr ession of a peptide DNA delivery system. (C) 2000 Wiley-Liss, Inc. and the American Pharmaceutical Association