No abstract

In drying methods that did not involve a freezing step, good storage stability of Medi 534 vaccine in the dried form was found with low SSA and low vaccine surface accumulation, both of which integrate into low fraction of vaccine at the surface. Ice appears to be a major destabilizing influence.

No abstract

No abstract

No abstract

A novel system for gene delivery, based on the use of DNA-gelatin nanoparticles (nanospheres) formed by salt-induced complex coacervation of gelatin and plasmid DNA, has been developed. These particles were spherical, with a size range of 200-700 nm, contained 25-30% (w/w) DNA, and were stabilized by cross-linking of gelatin. As a consequence of being controlled by the cross-linking density of the gelatin matrix, the average release rate of DNA from nanospheres synthesized under standard conditions was 2.2%/day in serum. Nanosphere DNA incubated in bovine serum was more resistant to nuclease digestion than was naked DNA. Various bioactive agents could be encapsulated in the nanospheres by ionic interaction with the matrix components, physical entrapment, or covalent conjugation. Transfection of cultured cells with a luciferase plasmid was enhanced by conjugating human transferrin onto the nanosphere and coencapsulating the endolysolytic agent chloroquine. Under our experimental conditions, gene expression in mice subsequent to intramuscular injection of nanospheres containing 1 microg of a beta-galactosidase plasmid was greater and more prolonged than was observed after injection of an equal amount of naked DNA or DNA complexed with Lipofectamine.

No abstract

No abstract