Complexes formed between polyelectrolyte and acetylated cationic dendrimers

Abstract

Gene therapies are receiving a revival, especially because of the potential for use in cancer and infectious disease vaccination. However, effectively condensing and maintaining deoxyribonucleic acid (DNA) carriers for gene therapy are used, such as dendrimers. The penetrable sphere model developed by Qamhieh et al., explain the interaction between linear polyelectrolyte (LPE) and an ion-penetrable sphere was employed to study the complexation of negatively charged DNA and acetylated dendrimer. Throughout the study, we emphasized the effect of acetylation on two types of complexations: single dendrimer-DNA chain complex and multiple dendrimers-DNA chain complex. The interaction between three different DNA lengths: L = 90 nm of 265; L = 184 nm of 541 bp; and L = 680 nm of 2000 bp individually with the poly (amido amine) (PAMAM) dendrimer of generation 5 was studied. For a single dendrimer-DNA complex, the number of condensed monomers around the dendrimer and the fraction of optimal length wrapping around the dendrimer was studied. It was found that by increasing acetylation, the number of condensed monomers and the fraction of optimal length decreased. For multiple dendrimers-DNA complex, the optimal length wrapping around the dendrimer and the linker that forms between complexes were studied. As a result, with increasing acetylation, the will shorten while the linker will increase significantly. The acetylation also affected the number of turns wrapping around the dendrimer and the net charge of the complex for single and multiple dendrimer-DNA complexes, and it was found that the longer the chain length, the more turns there are around the dendrimer. The net charge of all complexes was negative due to increased acetylation. In this study, it is revealed that the developed model is suitable for demonstrating the complexation between the dendrimer and the DNA.