[Mirus -- Delivery: Recharging cationic DNA complexes with highly charged polyanions & delivery to tissues in vivo: the intravascular approach.
Continuing on the delivery kick, here are two approaches from Mirus. Maybe ALNY should take its cash and just start munching these private delivery companies . . . or maybe we'll see partnerships . . .
>>Gene Ther. 2003 Feb;10(3):261-71.
Recharging cationic DNA complexes with highly charged polyanions for in vitro and in vivo gene delivery.
Trubetskoy VS, Wong SC, Subbotin V, Budker VG, Loomis A, Hagstrom JE, Wolff JA.
Mirus Corporation, 505 S. Rosa Road, Madison, WI 53719, USA.
The intravenous delivery of plasmid DNA complexed with either cationic lipids (CL) or polyethyleneimine (PEI) enables high levels of foreign gene expression in lung. However, these cationic DNA complexes cause substantial toxicity. The present study found that the inclusion of polyacrylic acid (pAA) with DNA/polycation and DNA/CL complexes prevented the serum inhibition of the transfection complexes in cultured cells. The mechanism mediating this increase seems to involve both particle size enlargement due to flocculation and electrostatic shielding from opsonizing serum proteins. The use of pAA also increased the levels of lung expression in mice in vivo substantially above the levels achieved with just binary complexes of DNA and linear PEI (lPEI) or CL and reduced their toxicity. Also, the use of a "chaser" injection of pAA 30 min after injection of the ternary DNA/lPEI/pAA complexes further aided this effort to reduce toxicity while not affecting foreign gene expression. By optimizing the amount of pAA, lPEI, and DNA within the ternary complexes and using the "chaser" injection, substantial levels of lung expression were obtained while avoiding adverse effects in lung or liver. These developments will aid the use of cationic DNA complexes in animals and for eventual human gene therapy.<<
>>Curr Opin Mol Ther. 2003 Aug;5(4):338-44.
Plasmid-based gene delivery to target tissues in vivo: the intravascular approach.
Hagstrom JE.
Mirus Corporation, 505 South Rosa Road, Madison, WI 53719, USA. JimH@genetransfer.com
Over the past several years, significant progress has been made in the development of non-viral methodologies that can effectively deliver genes to target tissues in vivo. One of the most surprising successes has been the discovery that naked plasmid DNA (pDNA) can be delivered into tissues such as liver and muscle with high efficiency using the vascular system. The key breakthrough involved the realization that pDNA could be injected rapidly into blood vessels (using increased volumes) in a manner that facilitates extravasation of the DNA solution outside the blood vessel wall. The extravasation process places the DNA in contact with the plasma membranes of the underlying parenchymal cells of the target organ. This intravascular delivery technique, termed 'hydrodynamic delivery', has become established as the primary non-viral methodology for delivering pDNA expression constructs to target tissues in vivo. This review highlights many of the most recent studies in which increased volume/rapid injection procedures have been used. These include studies in which the technology was used as a new and powerful tool to address in vivo gene expression questions, as well as numerous studies that were designed to better understand or improve the methodology. It is these scientific efforts that have served to fuel the development of this delivery technology from simply an interesting phenomenon to a highly useful and broadly used gene delivery methodology.<<
Cheers, Tuck |
