Preparation of Effective and Safe Gene Carriers by Grafting Alkyl Chains to Generation 5 Polypropyleneimine

Abstract

Abstract. Gene therapy is a novel method to treat a variety of diseases including genetic disorders and cancer. Nonviral gene carriers have now gained considerable attention as gene carrier systems. Polyamidoamine (PAMAM) and polypropyleneimine (PPI) are the two most widely used denderimers in gene delivery studies. The aim of the current study was to investigate the effects of modification of generation 5 polypropyleneimine (G5 PPI) dendrimers with alkanoate groups as hydrophobic moieties on DNA transfection and cytotoxicity. Six, 10, and 16 carbon derivatives of bromoalkanoic acids were conjugated onto PPI with 10%, 30%, and 50% of surface amine grafting. Ethidium bromide exclusion assay results proved the ability of modified carriers to condense DNA. Transfection assay showed higher DNA delivery potential for 30% and 50% grafting with decanoate moieties compared to native G5 PPI and Superfect TM . 3-(4,5-Dimethylthiazol-2-yl)-2,5-di phenyltetrazolium bromide (MTT) and apoptosis experiments showed lower toxicity for modified carriers compared to unmodified PPI. The hemolytic effect of grafted carriers was not significantly different from G5 PPI. Size and zeta potential measurements revealed that polyplex size was less than 200 nm and electrical charges were in the range 14-25 mV. The hydrophobic modifications improved transfection activity and toxicity of G5 PPI without negatively affecting hemocompatibility. These modified carriers are therefore promising candidates for further in vivo investigations.

Cationic Materials for Gene Therapy: A Look Back to the Birth and Development of 2,2-Bis-(hydroxymethyl)Propanoic Acid-Based Dendrimer Scaffolds

“…The ethidium bromide exclusion assay proved the ability of modified carriers to condense DNA, while the transfection assay showed higher DNA delivery efficiency compared to that of pristine G5 PPI and Superfect TM (Qiangen, Milan, Italy). 3-(4,5-Dimethylthiazol-2-yl)-2,5-di phenyltetrazolium bromide (MTT) and apoptosis experiments showed lower toxicity for modified carriers compared to unmodified PPIs [138]. Additionally, arginine-conjugated PPIs were prepared as non-toxic and efficient gene delivery carriers [139].…”

“…Important structural modifications have been made to improve the TE and reduce PPIs' toxicity. Hashemi et al reported the modification of a G5 PPI with C6, C10, and C16 alkanoate groups inserted as hydrophobic moieties [138]. The ethidium bromide exclusion assay proved the ability of modified carriers to condense DNA, while the transfection assay showed higher DNA delivery efficiency compared to that of pristine G5 PPI and Superfect TM (Qiangen, Milan, Italy).…”

Dendrimers as Drug Nanocarriers: The Future of Gene Therapy and Targeted Therapies in Cancer

“…A small library of alkanoate-modified PPI G5 dendrimers was developed and tested for their ability to transfect DNA to neuroblastoma Neuro-2a cells. It was shown that a balanced hydrophobic surface modification results in improved transfection, low cytotoxicity, and hemotoxicity [124]. Much larger modifications of PPI dendrimers in order to increase their efficiency as gene carriers have been made by a team of researchers from The State University of New Jersey [123][124][125][126].…”

Evaluation of anti-cancer activity of PLGA nanoparticles containing crocetin

“…Apoptotic cells were determined by staining using the propidium iodide (PI) method described elsewhere (Hashemi et al 2015). In brief, MCF-7 cells were seeded at a density of 2 Â 10 4 cells per well in 48-well plates.…”