Physicochemical and biological properties of self-assembled antisense/poly(amidoamine) dendrimer nanoparticles: the effect of dendrimer generation and charge ratio

Alireza Nomani^1,6, Ismaeil Haririan^1,5, Ramin Rahimnia^2,4, Shamileh Fouladdel², Tarane Gazori¹, Rassoul Dinarvand¹, Yadollah Omidi³, Ebrahim Azizi^2,4

¹Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran; ²Molecular Research Lab, Department of Pharmacology and Toxicology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran; ³Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran; ⁴Department of Medical Biotechnology, School of Advanced Medical Technologies, Tehran University of Medical Sciences, Tehran, Iran; ⁵Biomaterials Research Center (BRC) Tehran, Iran; ⁶Department of Pharmaceutics, Faculty of Pharmacy, Zanjan University of Medical Sciences, Zanjan, Iran

Abstract: To gain a deeper understanding of the physicochemical phenomenon of self-assembled nanoparticles of different generations and ratios of poly (amidoamine) dendrimer (PAMAM) dendrimer and a short-stranded DNA (antisense oligonucleotide), multiple methods were used to characterize these nanoparticles including photon correlation spectroscopy (PCS); zeta potential measurement; and atomic force microscopy (AFM). PCS and AFM results revealed that, in contrast to larger molecules of DNA, smaller molecules produce more heterodisperse and large nanoparticles when they are condensed with a cationic dendrimer. AFM images also showed that such nanoparticles were spherical. The stability of the antisense content of the nanoparticles was investigated over different charge ratios using polyacrylamide gel electrophoresis. It was clear from such analyses that much more than charge neutrality point was required to obtain stable nanoparticles. For cell uptake, self-assembled nanoparticles were prepared with PAMAM G5 and 5’-FITC labeled antisense and the uptake experiment was carried out in T47D cell culture. This investigation also shows that the cytotoxicity of the nanoparticles was dependent upon the generation and charge ratio of the PAMAM dendrimer, and the antisense concentration had no significant effect on the cytotoxicity.

Keywords: poly(amido amine) dendrimer, PAMAM, cytotoxicity, cell uptake, antisense oligonucleotide, epidermal growth factor receptor