Evaluation of cationic dendrimer and lipid as transfection reagents of short RNAs for stem cell modification.

Nowadays a large number of clinical trials suffer from lacking an efficient method for drug delivery into target cells with minimal side effects. Due to the great significance of this issue in novel and effective therapies, more attempts are required in order to distinguish better conditions for biomedical drug delivery. Since embryonic stem cells (ESCs) are under scrutiny of many new studies, development of novel methods for their genetical and functional modifications is of great value. On the other hand, the application of short nucleic acids in new therapeutic approaches is increasing. In this study the efficiency of small interfering RNA (siRNA) uptake with two transfection reagents generation five of polyamidoamine dendrimer (PAMAM G5) as a cationic dendrimer and N-[1-(2,3-dioleoyloxy)]-N,N,N-trimethylammonium propane methyl-sulfate (DOTAP) as a cationic lipid and one commercially available reagent were evaluated in mouse ESCs using flow cytometry. Prior to the cellular investigations; atomic force microscopy; gel electrophoresis; siRNA binding and release assays; and size and zeta potential measurements were utilized to characterize the physicochemical properties of reagent-siRNA nano-complexes. The safety of the nano-complexes was subsequently assessed by MTT assay. Functional effects of siRNA (complementary strand for OCT4 transcript) transfection in ESCs with the mentioned reagents were analyzed using a quantitative real-time polymerase chain reaction (qPCR). Surprisingly DOTAP at higher molar ratios and PAMAM at lower molar ratios could successfully knock down the OCT4 transcription relatively better than commercial reagent. Our findings supported the appropriate efficiency of the mentioned transfection reagents for short nucleic acid transfection. From a clinical point of view, this research helps allocation of short nucleic acids into stem cells therapies.