The present invention concerns a novel composition comprising a nucleic
acid; and a chitosan containing branching groups covalently linked to the
amino groups wherein said branches are selected from the following
groups; alkyl with 2 or more carbon atoms, monosaccharides,
oligosaccharides or polysaccharides. The composition is particularly
useful as a non-viral gene delivery system. The composition facilitates
the introduction of the nucleic acid into the cells to which it is
administrated, as well as the expression of the function of the nucleic
acid.
