Papers by Keyword: Spermine

Abstract: Chitosan (CS) is a biodegradable and highly positive charged polymer that can be utilized as a non-viral vector for gene delivery. However, its transfection efficiency is low. Spermidine (SPD) and spermine (SPM) are ordinary polyamines found in almost all living organisms. Their structures contain tri- and tetra-amine, respectively. The present study aims to elucidate the effect of SPD or SPM on transfection efficiency and cytotoxicity of CS/DNA complexes in human cervical carcinoma (HeLa) cells. The ternary complexes (CS, DNA and SPD or SPM) at different weight ratios and mixing orders were formulated and tested on transfection efficiency. Their particle sizes and charges were also estimated. CS that has a molecular weight of 45,000 Daltons and degree of deacetylation of 85 was able to form complete complex with plasmid DNA expressing enhanced green fluorescence protein (pEGFP-C2) at weight ratio of 4. The SPM/CS/DNA (1:4:1) and SPD/ CS/DNA (512:4:1) complexes illustrated the greatest transfection efficiency. Moreover, the transfection efficiency was affected by the mixing order between CS, DNA and SPD or SPM. For cell toxicity experiments, more than 85% the average cell survival of the complexes were detected by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) cell growth assay. These findings suggest that addition of either SPD or SPM to CS before forming ternary complexes with DNA may significantly improve gene delivery potential in vitro.

Abstract: Vectors are vital aspect of gene delivery system which decides the success of gene therapy. Efficient transfection with minimum or no toxicity, are two principal aims of any gene delivery system. In this our study, we rationally developed biodegradable water soluble poly(ßamino ester) (PAE) based on spermine (SPR) and poly (ethylene glycol) (PEG), by Michael-type addition reaction and further studied for its potential as a gene carrier. Confirmation of synthesized PAE was done by proton NMR spectroscopy. In gel retardation assay, the PAEs have shown good DNA binding ability over wide range of polyplexes. The addition of PEG over SPR resulted in a novel PAE with higher degree of safety and transfection efficiency as compared with polyethylenimine 25K (PEI) when studied in 293T human kidney carcinoma cells.