2022 Annual Meeting

Supramolecular Polyamine Carriers for Gene Delivery

Gene editing technologies have emerged as a promising therapeutic tool to correct mutations that cause diseases. Unfortunately, genetic constructs cannot penetrate mammalian cells spontaneously. With over millions of years of evolution, viruses can infect cells efficiently by using their unique structures. Researchers have utilized viral capsids to encapsulate and deliver therapeutic genes into cells. Although viral vectors are excellent gene carriers, they present inherent risks restricting their use in humans. Inspired by viral vectors, different nanocarriers have been investigated. For gene delivery applications, non-viral carriers must enter our immune system, break through multiple biological barriers, enter the cell, and release the therapeutic gene. Here we synthesized polyamine assembled nanocarries (PANs) for gene delivery applications.

PANs are prepared on the basis of the interaction between the positively-charged poly-allylamine hydrochloride (PAH), oleic acid and phosphate salts in saline buffer solution (PBS) by electrostatic and hydrogen bonding interactions. The size of PANs is controlled by varying the molar ratio between PAH and phosphates. PANs are stable at pHs from 6 to 8. Below pH 6 or above pH 8 PANs disassemble into molecular components. This pH-dependent response makes PANs very attractive for endosomal delivery of genes, as they are expected to disassemble at under endosomal conditions (pH = 5.5), releasing the cargo. To demonstrate the capability of PANs as gene delivery carriers, we encapsulated the gene editing tool piggybac transposon (PBCAG) following electrostatic complexing. We studied encapsulation efficiency through gel electrophoresis and UV-Vis Spectrometry. Tranfection efficiency was evaluated in vitro in human embrionic kidney cells (HEK293) using flow cytometry and confocal microscopy. The transfection efficacy shown for PANs is comparable to Lipofectamine reagents causing minimum cytotoxic effects. These very promising findings highlight the potential ability of PANs for future in vivo gene delivery applications.