Investigation of the efficacy of polyethyleneimine cross-linked non-reducing oligosaccharides in gene delivery to cancer cells

For gene delivery, cationic polymers must balance two crucial parameters: transfection efficiency and cytotoxicity. Although PEI remains a widely used gene vector, its clinical translation has been hindered by significant toxicity concerns. In this study, three low-molecular-weight PEI derivatives modified with oligosaccharides, trehalose, raffinose, and stachyose, are referred to as TRON-PEI, RAON-PEI, and STON-PEI, respectively. The potential of these polymers as safe gene delivery systems was explored and the influence of oligosaccharide modifications on the transfection efficiency of PEI-based vectors was examined. The physicochemical properties of the three PEI variants, including their ability to bind pDNA, cytotoxicity, zeta potential, and complex size, were analyzed. The experimental results revealed that oligosaccharide-modified PEI polymers effectively condensed pDNA into nanoparticles with diameters ranging from 106 to 142 nm. Among these variants, RAON-PEI-3 and TRON-PEI-3 exhibited optimal performance, achieving high transfection efficiency with minimal cytotoxicity across multiple cell lines (HeLa, MHCC-97H, and HepG2). Cellular co -localization and molecular docking assays demonstrated that the three vectors could successfully bind to pDNA and that the three polymers were able to target receptor proteins (ASGP-R and galectin-2) on the membrane surface of cancer cells. In addition, the cellular co-localization assay successfully verified that RAON-PEI-3 and TRON-PEI-3 were capable of rapid lysosomal escape and mitochondrial targeting. When complexed with the p53 plasmid, these vectors successfully mediated tumor cell apoptosis, as confirmed by western blotting and live/dead assays. Our results demonstrated that oligosaccharide modification represents a promising strategy for developing PEI-based gene delivery systems with enhanced safety profiles and therapeutic potential.