ABSTRACT
Cationic polymers possessing primary amine groups are inefficient in transferring nucleic acids into eukaryotic cells. With appropriate chemical modification, namely glycolylation of the amine groups of polylysine and polyallylamine, the actual number of free amino groups was decreased, hydrophilic residues were introduced, and the cytotoxicity of both polymers decreased significantly. Furthermore, in the case of polyallylamine, its ability to mediate gene transfer into cells increased by several orders of magnitude. Transfection efficiency was found to be dependent on the substitution level of amino groups and reached highest levels in the presence of lysosomotropic and/or fusogenic agents. At optimal conditions, glycolylated PAM was shown to be as efficient as the linear polyethylenimine of 22 kDa.
Subject(s)
DNA/administration & dosage , Gene Transfer Techniques , Polyamines/administration & dosage , Polyamines/chemical synthesis , Carcinoma, Hepatocellular/genetics , DNA/genetics , DNA/metabolism , Dose-Response Relationship, Drug , Epithelial Cells/cytology , Epithelial Cells/metabolism , Genetic Vectors , Glycolates/chemistry , HeLa Cells , Humans , Liver Neoplasms/genetics , Lung/cytology , Lung/metabolism , Lung Neoplasms/genetics , Molecular Weight , Polyamines/toxicity , Polylysine/administration & dosage , Polylysine/chemistry , Polylysine/toxicity , Transfection/methods , Tumor Cells, CulturedABSTRACT
In the cardiovascular system, nitric oxide (NO) is involved in the short and long-term regulation of haemodynamics, and in a number of their pathological alterations. Investigation into the biochemistry of NO-synthase isoforms has confirmed that they also all produce superoxide anion (O(*)). The free radical NO can interact with many targets on which novel information has been recently obtained. The major results of these interactions are not only the well known activation of guanylyl cyclase, but also the formation of potentially cytotoxic peroxynitrite (ONOO(-)), and the formation of S-nitrosothiols and non-haem iron-dinitrosyl dithiolate complexes. Tissue O(2), O(*), low molecular weight thiols and transition metals (especially FeII) play a pivotal role in directing NO towards targets responsible for biological effects, or storage or release from these stores. In addition, circulating forms of NO have been proposed with S-nitrosation of blood proteins. All these mechanisms provide potential pharmacological targets for future therapeutic strategies.