Silane and amino acid functionalized PBAEs for enhanced gene Delivery: Synthesis, characterization, and transfection efficiency

This study aimed to synthesize, characterize, and evaluate the transfection efficiency of end group-modified branched poly (R-amino ester) (PBAE) based polymers containing silane groups to be used as gene carriers. Branched PBAE polymers were synthesized using bisphenol A ethoxylate diacrylate, diethylenetriamine, and N-[3-(trimethoxysilyl)propyl] ethylenediamine, and various amino acids (histidine, isoleucine, serine, methionine, phenylalanine, arginine) were added for end group modification. The structures of the polymers were confirmed by nuclear magnetic resonance (NMR) and Fourier-transform infrared spectroscopy (FTIR) analysis. Nano-particles were prepared using the nanoprecipitation technique, and their plasmid DNA complexing and protection capacity and endosomal escape abilities were determined. Finally, the cytotoxicity of the nanoparticles on HeLa and HEK293T cell lines was tested by the MTT test, and their transfection efficiency was tested by flow cytometry and fluorescence microscopy. All the tested nanoparticles showed lower toxicity in HeLa cells than in HEK293T cells. Transfection efficiency followed an increasing order, starting from the linear PBAE, progressing to silane modification, and subsequently with modifications by histidine, isoleucine, serine, methionine, phenylalanine, and arginine. This study highlights the potential of silane and amino acid-functionalized PBAE polymers as gene carriers and the impact of these modifications on transfection efficiency.